In the afternoon I went back and got the car. After work I left the Frankenheap there and drove this car home, bringing home a returned power tool in its (larger, and empty) trunk. It drove well, nice and strong. I did notice:
...I got the neighbors to run me back down to work after dinner, and we picked up the other car. (I rode in the back of the SEL on the way down, and he drove the Frankenheap back—he'd been wanting to see how it drove since he has a project car almost exactly like it.) Additional observations:
Change the fuel filters first. On an SDL, when the fuel filters are partially plugged, the first symptom is that upshifts don't happen unless you let off the pedal.
I cleaned the failed Gorilla Glue off the torn red-dot keyhead and re-glued it back together with something more suited for the purpose: Shoe Goo.
At lunch I tried to get the car licensed, but they say I can't until I get a stink test. (She did say that the BoS, signed Nevada title, and SoV form [above] were all I'd need to make the transfer, in addition to the State-mandated prostate exam.) OK, perhaps tomorrow. So in consolation, and because I wasn't too far away, I swung by the U-Pull and went shopping. They had a 123 manny-tranny 240D, so I grabbed its special cruise control amplifier for the parts pile. The 126 300SD supplied a rear-view mirror and a dome light, and the 201 190E supplied a too-small but better than nothing trunk carpet, a SRS-equipped seat belt assembly, and an EHA valve to sit in reserve. (There were no intact brake lamp housings or shifter knobs to be had.) The mirror and the seat belt are the biggies this car needed. It was sunny and fairly warm when I hit the yard, I debated leaving my coat in the car with my hat, but I didn't. Good idea, but bad idea leaving the hat: as I was working out there a huge lightning and hail storm blew in; I got pretty wet, and working out in a sea of metal was a bit disturbing. On the way back to work I passed several wrecks on the freeway, the accumulation of slush on the road was pretty significant and I'm sure visibility had been bad. Jill reported that as she was coming through town at around that time she was seeing 1" hailstones! (I think that's an exaggeration, but I'm sure they were large. I was seeing 1/4" stones where I was. The sheeple were probably regretting taking off the snow tires as State law mandates be done by the end of today (if studded). But it was snowing here recently, and the half inch of slush today seems to be a snow tire worthy event. The Law, as has been so ably noted before, is [at times] an Ass.)
Jill called me shortly after my return to work to let me know that she was home, and she seemed excited to see the big white car out in the driveway. My ruse worked! She thinks it's the SDL coming back to life. I wonder how long I can pull that off?
Regarding the possibility of eventually making an SDL out of an SEL I hit the State's web site on the vehicle emissions testing program, and was unable to find out anything so I sent in a query:
I see no information here on the ramifications of converting a vehicle to a different fuel type. (Gas to diesel, or vice-versa, or to/from propane, or even hybridization.) What are the regulations on such conversions?I got back this:
In order to legally replace an engine with another fuel type, the vehicle must have been certified by EPA for that fuel type and all emission system components are intact and operation[al]. If you are converting a vehicle to exclusively run on propane, you will need the state patrol to inspect the vehicle first before licensing the vehicle. If the vehicle is dual powered, then you will need to pass an emission test every other year as regulations mandate.Tom Olsen, Unit Manager
NWRO Emission Check Program
When I got home I checked, and the new seat belt tongue latched into the buckle so it's looking pretty good as a replacement so far.
Since I was back there I had a look at the reading lights. They both worked for me then, I think the one just had a dirty switch contact. They didn't fit right, though. I had a closer look, and removed them both and swapped them over to their correct sides. They fit much better that way!
Next was the wonky switch panel on the driver's-side rear door. It just wouldn't stay in. After removing it and playing around for awhile, I figured out that the problem is that it's a right-side panel jammed into the left side! (Part #126 766 08 91, should be #126 766 07 91.) I'll have to get a new one, that's probably going to be a dealership item. While I was there I corrected the switch positions on the left and right sides. The loose panel will just have to stay loose until I get a replacement, I'm not going to try gluing it back in place like one of the PO's did!
Still in the back, I replaced the missing cigar lighter element on the driver's side with one from the junkbox. Its illuminating bulb was burnt out, so I replaced it with the one I bought yesterday.
Moving up front I replaced the burnt-out 9004 passenger-side headlight with the one from my spares pile. (I'll try to get another one today.) I also replaced the passenger-side fog lamp rear hatch cover, which I found in the glovebox. I replaced a couple of burnt-out fuses, and restocked the spares in the fuse box. (I blew one this morning trying to run the wipers with them frozen to the glass.)
The ruse continues to work. Not only did Jill pass it this morning on her way out, with me in it and working on the seat belt, but when she came back I was still in it. I invited her to sit inside with me. It was even running. She still thinks it's the SDL. She: "Did you remember what was wrong with it?" Me: "Oh, I'm figuring it out." She even walked by the open garage, where the SDL was certainly visible. I'm a-gonna pay for this one! :-)
...At lunch I went and got the stink test done, which passed. I then went and got it licensed, $255 with tax and plates. (Ouch.) I then went back to the U-Pull. I grabbed the 126's non-SRS seat belt, which has the special mounting hardware at the shoulder point, I might be able to combine it with the one I put in today. I got its taillights too, to lay in as spares for the two 126's we now have. (That was $30, let's hope we never need them.) I got the hump's plastic bolt covers, but they're a different style. We'll see if they'll work or not. I also stopped at the liquidation outlet and got two 9004's and an H3. 70% off today.
...After work it was snowing again and I hit the wipers. Skreeeeeeech! Oops, one of the blades was working out of its socket. I put it back, it seems to stay now—I'm guessing it wasn't snapped in all the way last time it was replaced. I tested the fanfare horn (loud and soft horn settings), it works. The fourth seat warmer also works, I turned it on and felt the seat later.
As it was starting to snow harder I scraped around and found the extra new antenna grommet for the 190D that I'd somehow ended up with, and fit it into the hole in the fender. I then poked the antenna up through it. That'll keep out the worst of the moisture. I have some work to do to actually install this thing correctly.
...The SRS and ABS lights don't come on with the key, so after work I pulled the OVP relay to check out it and its fuses. There are two fuses on top of this vintage relay, it looks like a triple circuit: one pair (87E & 87L, two contacts each) relayed and another one (30a, two contacts) continuously powered. This is the 9-pole variation in the ETM. The relay is stamped with 091203, and has a Bosch (?) logo and a printed part number 89 7236 000 on one side, and printed legends of 10A, 12V, and "made in Hungary". There is a schematic on the other side, and a pin layout legend on the front. The back has two mounting ears spot-welded to it. I was unable to open it up to check its internal solder joints, but I did buff its contacts, and those of the (intact) fuses. The thin (think paper clip wire) rubber O-ring seal for the fuse hatch fell apart when the hatch was opened, we'll do without it I guess. There was something weird about the socket in the car, it seemed oddly attached to the car, but it was a little too dark for me to see what was going on. I'll know more in the morning, when I reinstall it.
I checked the online NADA blue book, and according to them I paid just about what the car was worth. That's a pleasant change.
I put back the OVP relay. With light I could see that this relay's electrical socket, unlike what I've seen before in this area, is loose on a pigtail and the relay's mounting ears snap into a retaining clip. I could also see that its two 87L contacts, and one of the 30a contacts, are not used in this car.
I pulled the driver's-side B-pillar cover and re-glued its skin using contact cement. Leaving it open for reference I then took apart the passenger-side B-pillar and swapped mounting hardware from the belt I got Wednesday. With the correct hollow bolt head and the metal spacer it is again possible to slide the belt shoulder height adjuster. Though it's still not quite right it'll do until (if ever) I run across the proper belt. I then put the pillar covers back. I replaced the missing driver's door courtesy light, but that was my last spare. I'll have to get more sometime.
I then swapped the plastic seat belt track bolt-head covers (that I got from that older donor 126) for the missing/broken ones in this car. Though they're black rather than color-matched, and more pokey/square than what belongs there, I think it looks better anyway. Again, at least until/unless I get a better match somewhere else.
On the way to work I thought the cold lockout on the HVAC was broken because the fan started up immediately, but after work I checked further and found that the LOW fan button also overrides the lockout. When on AUTO the HVAC was off until the engine warmed up. Interesting. The blower fan is a bit noisy, sounds like brush noise. On the way home I checked the ABS on the gravel road, it doesn't work. I also checked the ATF level after I got home, and decided that perhaps it was a bit low, so I put in 1/2 quart. We'll see if that makes any difference on its shifting.
...The ruse is over. Daniel threw up in the Chicken Wagon today, and we needed to go to a rehearsal at church. Since the CW's carpet was drying she asked if we could take the white car. "OK," sez I. (My preference would have been to hold off letting her travel in it for another week or so.)
So she gets in. "When did this shift knob get all messed up?" "I dunno," I reply. "Huh." We got all the way to the church, then she noticed the center console storage tray. "I don't remember this." "You wouldn't," I say. "Why not?"
I just couldn't hold off any longer. "Because this isn't the same car." It took a few seconds for that to sink in. I don't think she's entirely happy, imagine that. I'm sure that had I intended to I could have kept the ruse going much longer than this. But the danger is that she'd put diesel in it the first time she took it out.
Oh, and its shifting is unchanged.
I then threw all the tools and work clothes in the trunk and went off to the U-Pull to see if I could get a steering box for the Chicken Wagon.
...When I got back, and it had been parked for awhile, I noticed a green puddle of antifreeze under it. Oh-oh! (Probably the water pump, I'll have to check that.)
Costco no longer carries the good heavy rubber floor mats we like, so I stole the ones out of the SDL since we're not driving it.
No sign of antifreeze leaking.
...Cancel that! At lunch time there was a green puddle under the car, and I could see it dripping from the water pump. Time to order a new one!
I popped the hood and started digging down in a bit in preparation for the water pump replacement and suspension pump re-sealing. I found torn-off rubber mounts on the air cleaner and the idle control solenoid, so I cleaned them with carburetor cleaner and glued them back on with Shoe Goo. The idle air hose was also cracking badly, so I cleaned and glued it too. It ended up nearly potted in the stuff, but I don't think it leaks now.
All the wires under the hood have hand-numbered masking-tape flags hanging off of them. This suggests that the engine was pulled at some time, presumably not at a dealership.
There is a four-way vacuum splitter at the front firewall with one open leg and nothing nearby that looks like it came from it. Looks like it may be plugged, though, I'll have to look into that. Maybe somebody didn't have a three-way on hand?
This sucks. I'm at 4.5 hours on this job and I haven't even got the bad pump out yet. A good idea from the mailing list:
Cut the bolt, and replace it with a narrow-head internal-hex (Allen) type that can be removed through the notch in the future?That'd be good for next time!
I then power-washed the area and flushed the engine block.
I then removed the suspension pump from the engine. That takes a 17mm flare wrench to remove the high-pressure line, and a 17mm socket to remove the banjo bolt on the low. An Allen wrench removes the four long bolts from the face of the pump, liberating it. You need a 13mm socket to loosen the clamp on the high-pressure line, else you don't have enough slack to remove the pump. With the pump out you need to cork the high-pressure line else the suspension oil reservoir will empty onto the ground. I lost quite a bit of oil before I got this done.
With the pump out you can remove the remaining two Allen bolts (the short ones) and pry the lid off the pump. The shaft and cam can then be pushed out from behind with your thumb. I cleaned everything with brake cleaner, it was very grimy. I took pains to keep the four pistons from getting dirty during this. (The pump is a small radial design, similar in configuration to the R4 air conditioning pump that Mercedes [and GM] used to use.) The three old seals (of diverse sorts) can now be removed: scrape off the paper body seal (114 236 00 80), chisel out the large-diameter (but small cross-section) O-ring body seal (010 997 43 45) being careful not to damage the channel or the face, and pry out the shaft seal (004 997 01 47). The O-ring was very hard, I couldn't even tell that it had been an O-ring in the beginning, and was most likely the source of the leak.
I then cleaned everything again and tapped the new shaft seal in gently with a hammer. The shaft may then be lubed and twisted back into place. (You need to gently pry the piston drive ring into place to let the cam go into it while you do this. With the shaft in place you can then pry again to slip the brass bushing between the drive collar and the cam, it doesn't really work to try to install it all in one shot, tolerances are very tight.) Then I put the O-ring in the channel and bolted the cover back on with the two small bolts. The trickiest part is getting the body of the pump installed back on the engine with the drive ears mating with the distributor drive while keeping the new paper body seal in place. (You need to put the high-pressure line back on the pump first, though not tightened down yet, then twist and wiggle until it drops into place.) That's not too difficult, though. I then bolted everything back down and reinstalled and tightened the hoses and their braces, then sprayed everything off again with cleaner. Done.
The large-diameter O-ring keeps suspension oil from leaking out of the head of the pump. The shaft seal keeps it from leaking into the engine crankcase, and the paper seal keeps the engine oil (and any vagrant suspension oil) from leaking out behind the body of the pump.
...In another session in the evening I scraped off the gasket surfaces and installed the water pump. That took a long time, due to the tenacity of the old gasket. I tried to be careful with the razor blade not to damage the metal surfaces. Once done I transferred the thermostat to the new pump, but used the new O-ring seal that came with the pump. (I made sure to install the jiggle valve up.) The two slightly-longer pump mounting bolts must go in where they came out, at the bottom and bottom-right of the water pump where the thicker bosses on the pump are else they'll bottom out in the holes and not clamp. I wire-brushed the rust off of the one very long bolt that goes through the body before reinstalling it. The new gasket had a small tear most of the way through at one point, that was very distressing to find. At least it was at the top and not the bottom, so any leak will be very visible. I used Permatex anaerobic sealer to goop the torn area before reassembly, it should be fine. I got the pump and thermostat housings assembled, and the radiator feed fitting partially installed before I had to quit again.
This job is turning out to be very slow!
...Later I went back to it, and got the radiator installed. I washed out the fins on both it and the condenser with the hose, they were both pretty clean (not like some I've seen). I left off the fan and shroud, since the glue was still drying. I bolted the fan pulley on and started the car. It started right up. I moved it just to show Jill that progress was being made. (Sort of a Mother's Day present.)
...I drove the car to work, etc. It worked fine. No sign of leaks, though the new water-clear suspension oil turned all dark. Needed more flushing, I guess! I stopped and bought a jug of Zerex G-05 antifreeze. I'll put that in after another flush cycle or two over the next few days to get out all the green.
...In the evening we took the car to a concert. The low-oil light started coming on, and we could smell burning oil when we got out. Some kind of leak thing going on?
I checked, and the engine oil level was fine. The level sensor must be lying, I may well need a new one.
...While driving to work today the brake boost failed suddenly. When I got to work I popped the hood, and found that the fitting on the check valve had snapped off, making for a rather large vacuum leak!
The ATF change made no difference in the car's shifting characteristics.
...When I got home after work I dumped the coolant, it looked pretty clear so it's time to use the Zerex. I removed the brake vacuum line and cleaned it with brake cleaner. I tacked the fitting back on with cyanoacrylate glue, then potted the whole thing in Shoe Goo. It should be ready to use by morning. The rubber boot through the mid firewall is torn, I'll glue that too once the potting sets up a bit.
...After a couple of hours I turned it over, cleaned, and potted the tear in the rubber boot.
While in the area, at the suggestion of a lister, I loosened the pull of the shift cable by about 1/8". We'll see if that makes any positive difference. The thing looked unmolested and otherwise as it should, so I don't hold out much hope for this. I thought that a maladjusted shift cable resulted in skewed shifts across the board, not just a problem with 1→2.
I also put in the Zerex G-05 and topped it off with water. So's not to wash away any coolant I was gentle with the refill, I may have not gotten it all the way full. So I filled the empty jug with water and put it in the trunk for topping off purposes.
...No, I lost the brake boost again on the way to work. The webbed glue holed, I'll have to re-do the job properly when I get home. I also note that the tranny cable adjustment has made it a little more palatable for regular driving, but if you romp on it at all it'll still go up and bounce off the rev limiter unless you back off the throttle to let it shift.
...When I got home I loosened the engine-side fitting and spun the hose around to match the bend of the other hose, thus closing up the crack, then I put a wad of glue over it. After it set up some I smeared a wad around the bottom too, and connected the hose to hold it in its final position, but loosely so as to minimize stress on the glue joint.
The Shoe Goo is just too soft for underhood use like this, plus I wasn't ever waiting for a full cure. Today at the U-Pull I nabbed some items from their latest 126 organ donor: a good shifter knob, a stiffer rear-view mirror, a trunk carpet, a clip to replace the missing fan shroud clip, a warning triangle, and a brake vacuum hose. I also got some dirty and bent grille trim strips from the car's broken grille. When I got home I tried out the new hose, but it was about 1" too short! Nuts. I pulled the failing glue off the original and tacked it back together with cyanoacrylate glue, this time making sure it was oriented the right way. I mixed up some 5-minute epoxy and coated it with that instead of the Shoe Goo. It wanted to run, so I kept it spinning slowly by hand until it started to firm up, then set it aside to dry.
I also got a factory sparkplug wrench (that'll probably go into Ethelred since it unfortunately has need), and a factory lug wrench which I can use in this car. I got the spark wires too, which I'll probably try in place of the existing ones to try to see if there's a problem there that is responsible for the intermittently rough idle.
I got out the warning triangle I got yesterday and wire-brushed off the rust. Then I painted the metal again, mostly I used a brush since I had to avoid messing up the 'printing' on the face or the plastic reflector surfaces. While that dried I glued the retaining tab on the triangle's mounting clamp that I had to break yesterday in order to get it out of the car. These were set aside to dry. I then removed the console surround, switches, etc., and removed the shifter knob. That's when I found that the new one was subtly different, and not likely to end up pointing right if I were to install it. I tried hand-sanding the scabrous top of the old one in order to clean it up for painting, that's when I found that it was actually leather-wrapped. (I think the original leather surface was ruined by hand lotion and/or DEET insect repellant.) I ended up pulling the top cap of leather completely off, exposing a pretty nice plastic surface. I lightly sanded it and then painted it (and the remaining leather) with black vinyl paint. It doesn't look too bad now. I cleaned up the PRNDS2 window and the rubber boot, then reassembled the shifter once it was all dry. That took a bit of fiddling.
The coin tray was really chewed at the bottom, through the color and into the substrate, so I mixed up a little paint to get a vaguely close color (that didn't really work) and brush painted the bottom. I then put the console back together, replacing the one missing ashtray screw. I left the Becker BE 1480, serial A 9532117, out as I need to get its security code input in order for it to work again. I then attached the now-dry (enough) warning triangle to the trunk lid.
I also replaced the passenger-side courtesy light fixture, since its mounting ear was broken off and it wouldn't stay in place. And I installed the new trunk carpet, and threw the lug wrench I got yesterday into the trunk after I wire-brushed off the rust. Then I replaced the rear-view mirror (again) with the better (stiffer) one I got yesterday. Even at 2× the price ($4) it is a good deal.
Not quite done for the day, I tried to install the $2 worth of spark plug wires I got yesterday, and found that they didn't fit. The distributor end sockets were too small. (This discovered only after I reworked one pulled-off socket to get it back together again.) Too bad, I had been hoping to diagnose the rough idle as being due to old spark plug wiring. There is a mess of glue on the driver's side valve cover where the wires are, not sure just why this would have been done but it's highly suspicious.
I then got out the salvaged grille trim strips from yesterday and had a look. Two were the right length for the missing pieces, and in about the same condition except for some mild bends, but most of the mounting tabs molded into the grille itself were broken off. So I used screwdrivers and my hands to straighten the strips, then glued them into place. Twist-ties served to hold them in place until the glue dried. They look pretty good now. Consistent with the rest, anyway.
She'd also left another window down some, a front one, so I pulled open the console and used the battery charger to run that one up too.
I checked, and I have enough juice to charge the AC. Can't, of course, without the key.
...At lunch I bought a window motor/regulator at the U-Pull. $17, that's a profit center piece obviously. The 'new' regulator is bent, as nearly all are. Junk pot-metal design. The nylon slider is also broken, though it's all there. That's not so good. Maybe with this I'll have enough pieces to throw together something that will work. I should order a new slider, but that'll take time.
So I called Rusty and ordered two sliders, so that I'd have a spare for next time one of those POS's breaks.
...At lunch I returned the unneeded window motor/regulator to the U-Pull and got my $17 back. (But not the $2 entrance fee, of course, nor my lunch break.) My fault for jumping the gun and buying parts in advance of diagnosis.
The center brake light fell apart on the test drive, the glue let loose in the oven heat of the closed car. The weatherstrip cement I used is apparently not that good in high temperature environments, or perhaps I didn't use enough. Anyway, I had recently found that I had another, mostly intact brake light assembly in a parts box, so I used that instead of frankenstein's monster that I'd pieced together earlier. (The rear cap retaining snaps were gone, of course, but otherwise it was in good shape.) I used more weatherstrip glue this time to hold the end cap on, and set it aside to dry.
I looked at the radio's wiring harness and labeled the radio's contacts with a Sharpie. (This so I can connect power to it on the bench. It needs 24 hours of power to snap out of its code-wait state.) I found a spare Becker plug in the parts pile, so it was even easy to hook up on the bench, which I did. Now it says to WAIT. Well OK then, see you tomorrow perhaps.
...Today I surfed and got some radio serial number decoder
applications, and after work I threw them at Virtual PC. The Becker
4-digit decoder becker4digit.exe suggested the code was
4140. The becker.exe program suggested 34141, as did
becker2.exe. All of these crapplications only accepted
the last four digits of the radio's serial number: 2117.
The becker9preset.exe suggested 24141, and also would
only accept four digits of the serial number. (The most likely code
is the first one.) Our office computer cluster[f**k] claimed there
were viruses in becker.exe
and becker4digit.exe, but I ran them anyway since they're
locked in a VPC box that I don't care much about.
I also finished putting the car back together except, of course, for the radio. That didn't take too long.
I then put the radio in the car, which was a lot of fun since there are so many wires to hook up and wad behind it. It CODE-ed again, but that's no longer a problem. The radio worked, even without an operable antenna. The front/rear fader is scratchy and noisy, and cuts out the right channel at the least excuse. Obviously it needs a good cleaning. The rear speakers make almost no noise at all except for a scratchy little whine, they're probably sun-rotted and blown. The door speakers work, as do the dash speakers. Success! I programmed the local FM stations into the presets.
...This evening we drove the car to an event. It worked well, and the radio was nice, as was the AC. Coming home at night I shut off the AC and radio and opened the sunroof. Nice.
In celebration I got out the touch-up paint and covered the worst spots I could find on a quick walkaround.
The ashtray in the LR door rattles horribly on the road, so I took it out and tacked its loose metal trim piece down with cyanoacrylate glue. We'll see if that improves anything too.
I pulled out the driver's under-dash panel, which was difficult as the plastic trims covering the screw heads were very sticky, they were close to breaking when they finally popped out. (These pry out starting from the outsides! That is, the extreme left and right edges when seated. If you pry from the wrong edge you'll break off the piece's retaining hook.) I'll need to lube those with teflon spray before reinstallation so that they don't break in future. The ABS plastic footrest, 126 688 11 06, was all broken up so I pulled it out (it's part of the outside carpet side panel) for gluing. (There's a hook on the side panel part, it pulls toward the rear of the car, and then away from the side wall and out. I broke it further figuring that out.) With the carpets out I vacuumed, there was a lot of dirt under there. Anyway, with that all out of the way I could then pull the cruise control amplifier, which shares a bracket with the Hella 004 545 07 32 8-pin warning module, also removed. (Disabling the interior courtesy lights as well.) It's all held in with only one 10mm nut.
It's your typical VDO 14-pin servo amplifier package, with customization plug. The ink-stamped (date?) code of 518 20/90 implies that it's the original unit. Scrawled on it in red grease pencil is a big 218 (maybe). Stamped into the case metal is:
20/90
12V
412 212/1/1
* Mercedes-Benz
005 545 05 32
The customization plug is labeled 19 90, a date code, along with
005 545 07 32 and VDO 519201/1/01.
I opened up the amplifier and found a change: instead of the usual digital or analog discrete circuitry there was a 40-pin DIP, possibly a microprocessor of some sort. (It could also be an ASIC. There's still plenty of discrete circuitry to go wrong though, including an LM2901 quad comparitor and several transistors, including an H-bridge for the servomotor.) The big DIP was labeled:
ITT V 8001-501 GermanyIt also had 32 and 0045: labels on it, sideways to the main markings. The board was (as is usual) conformally coated. It was hard to tell for sure through the coating, but many of the solder joints looked suspect. The board, while double-sided, has traces only on one side; the component side is a shielding ground plane. Zero-ohm resistors are used where necessary to route signals on the component side, I counted eleven. I ran out of time to proceed further today.
...This evening we drove to dinner in this car, my first time in it since the noise treatment, and I could tell that all the odd creaking was gone. Yay, Vaseline! The noisy ashtray handle was also quiet. Makes quite a difference in driving enjoyment.
Oops. There was a surge when I turned it on, then it seemed to act weird. Then I smelled magic smoke. I stopped the car and opened up the case, and smoke poured out. One of the motor drive transistors fried, ruining one of the PCB mounting pads. That's not good. I pulled out the coupled TO-126 pair, and found both transistors completely shorted. One is a BD-438, the other (unknown) was cooked into slag. The other similar physically-coupled pair on the board are an NPN-PNP complementary pair, I didn't pull them out to check the markings but I expect them to be the other leg of the H-bridge and exactly the same. The BD-438 is a PNP 4 A 45 V power transistor. The slagger is probably the complementary NPN device, BD-437. I replaced the BD-438 with a 2N4918, and the other one with a 2N5190, both from the junk box. These are not exact matches, but perhaps they will work. I had them on hand, anyway. I used heat-sink grease on them to help couple heat to the little metal clip. The PCB pad, though fried, still made enough contact to the Emitter of the NPN that I didn't have to use a jumper wire. The Fluke's diode test range showed the two devices acting appropriately in-circuit.
Obviously, however, a bit more care is called for in testing this. I need to resurrect the bench test harness, and fire it up with a current limiter first. These H-drive circuits are highly susceptible to frying if anything bad happens to the inverting base drives. Bad solder could certainly do this, so I resoldered this circuitry again.
On the bench the amplifier drew approximately 400 mA on average while driving the motor, and seemed to work correctly. No smoke, no excess heat. I'll need to check that there isn't anything in the car's wiring harness that'll cause a problem, but so far it's looking good.
The 'processor' takes a 4.19430 MHz (222 Hz) crystal, driven by pin 29 of the part and fed back in on pin 28. Probing around shows that the processor uses a 5 V supply, I think via a Zener diode somewhere on the board; there is no sign of a regulator. A strategically-located bypass capacitor implies that it takes 5 V power on pin 1, and ground on pin 21. Perhaps this can be of aid sometime in identifying the part, not that this would be of any use in finding a replacement since it's probably a masked ROM device. (If it's actually an ASIC there's equally little chance of ever getting a replacement.) With that pinout it's not an 8051 processor, I know that. While poking around on the board I did find a case-split 1N4005 diode, which I replaced with a brand-new identical part from my parts bin. (That's kind of unusual for me. The really odd thing was that the split part seemed to still be working.) The diode was probably ruined by excess current going through the H-bridge.
I opened up the customization module and found five resistors inside, one of them a zero-ohm job. Roughly what I would have expected.
I checked the wiring harness connections to the servomotor to make sure there was no power or ground fault, and it passed so I took it for a test drive. It worked perfectly, and held my 35 MPH set speed up hill and down. (Downhill it sped up some, but that's because of the sloppiness inherent in the torque converter.) I then hammered the aluminum case ears back down and reinstalled it in the car. I was short on time so I left the panel work for later. (Plus I have some gluing to do on the footrest.)
To get the gluing started I cleaned off a couple of the breaks and then tacked them together with cyanoacrylate glue, then bolstered one of the more fragile breaks (the floor mounting ear) with a piece of sheet metal and Shoe Goo.
...When I got home from work I did some more cleaning and gluing. I got the panel/footrest all glued together with cyanoacrylate glue, and I got some more Shoe Goo laid over some of the non-critical cracks. I'll use sheet-metal backing plates for the higher-stressed areas.
...After dinner I did some more cleaning and Shoe-Gooing. Two more sheet-metal backing plates across some stress breaks.
...And before bed I did one last cleaning and Shoe-Gooing. I found some more sheet metal (leftovers from one of the Frankenheap's preheater attempts) and made backing plates for the rest of the stress breaks. That used up just about all of that tube of Shoe Goo, so I guess I'd better be done. Tomorrow (or better yet, the next day) I could reinstall this thing.
Then I went out and removed the passenger-side under-dash panel, it was time to take a stab at the noisy aspirator motor. (The screw-hiding trim panel pries out from the outside edge [extreme right] first! If you pry from the wrong edge you'll break off the piece's retaining hook.) The panel came off easily enough, but the knee bolster was a bit recalcitrant. Eventually I figured out the problem, it was just caught on something. The passenger airbag is held in with one long bolt through a plastic-lined recess in the bolster, and comes out very easily. I didn't really need to take it out, however, but I didn't know that until I'd already done it. (The airbag bolt can be removed even with all the trim and panels in place.) One of the plastic ears on the air outlet that goes to the door was broken off so I cleaned it off and tacked it back on with cyanoacrylate glue, then I used pliers and a small screwdriver to dig enough Shoe Goo out of the 'empty' tube to glue it back, along with a small piece of reinforcing metal. I also used weatherstrip cement to reattach the foam collar (for the air outlet) to the knee bolster.
The aspirator motor (000 830 96 08) didn't want to come out very easily, it was wedged into a soft foam block. Eventually I got it out and lubricated it. (It wasn't easy to get open, and I don't know how successful the lubrication attempt really was.) The cover for the main blower was loose, one of the screws had fallen out. (It seemed to be the wrong size anyway.) I dumped the leaves and dirt out of the porcupine (blower speed regulator) that's in the air path, then I removed the blower motor to see if it could be serviced.
It looked OK, so I dripped a little oil into the bearings. Putting it back was interesting, it seems that it had been taken apart before and not put together correctly: the plastic was a little deformed and things didn't want to slot into their correct channels. (The blower housing fits very snugly, there are a lot of tongue and lip joints to mate.) Perhaps this is a replacement motor, installed carelessly? With a bit of fiddling I got the motor and the cover back on correctly and found that part of its problem was that a retaining clip for the rear corner was missing. I fabricated a new one out of some springy metal banding. That took awhile, but should help keep the housing airtight and quiet. I put the aspirator motor back in. When I fired everything up the aspirator was noisier than it should be, but I hope that the intermittent shrieking is gone. I really should get a new aspirator, but I hate to if it's not completely necessary. We'll see how it goes, now that I've R&R'd it once it would be easy to do again: you only have to remove the underneath panel and the knee bolster.
I checked under the floorboard and the airbag system is plugged in, so if it's non-functional that's not the reason. While I was there I vacuumed. I then put back the knee bolster, but I left out the rest until the glue can dry on the air outlet.
...In the afternoon I got impatient and put the car back together. I could have waited longer for the glue to dry but I think it'll be OK. We won't be driving it today so that'll keep most of the worst stress off of it anyway. I used spray teflon lube on the clips for the plastic trim strips that cover the screw heads. That should help them to come out next time. (Half of one center clip on the long passenger-side piece is missing, but so far hasn't seemed to cause any bowing.)
I made a small mistake and overtightened one of the hood release screws and cracked the tip off of the plastic body. Oops. I glued it back on with cyanoacrylate glue, we'll see if it stays together. (It's only cosmetic.)
While looking in the trunk for the panel mounting screws what should I find but two radio code cards! That would certainly have simplified things last month...
I checked again, and the coolant level is down a little more as is the suspension oil level. Engine oil level is up. No sign of any external leaks, however. Not good. I can blame the oil levels on a botched shaft seal on the suspension pump, but where's the coolant going?
After breakfast the sun was up enough to shine down into the engine compartment, and then I could see the sender: It's to the rear of the oil filter housing, and hard to reach behind an engine shock absorber. I pulled the connector off the sender with pliers and it popped right off the wire when I did so. It might have been that the wire was merely broken, so I took it apart to fix it. Unfortunately the connector shell (014 545 07 28) broke apart too, and its rubber boot (008 997 07 81) tore. Criminy. I checked the sender itself and it was grounded, which is as it should be. (The light comes on when it's open-circuited.)
I scraped and cleaned the area, then resoldered the connector back on. I did a pretty crappy job, but it's hard to do on your back underneath a car! I used some cyanoacrylate glue to patch the shell, and dregs of Shoe Goo dug out of the tube to patch the rubber cover. It'll have to do, and it did seem to seat securely back on the sender. When I tried the key the low-oil light was out, so perhaps this has cured the problem.
The cruise control worked flawlessly. The radio was fine, but at times would emit an intermittent very loud BRRRRR-AAAPPPPP sound that wasn't source-related, nor did it respond to the volume control. Post-preamp problem in the head unit? Rear-mounted amplifiers? Regardless, Jill wants a CD player so it'll get swapped out sometime.
I wonder if the single molded valve block traps too much heat around the coils for reliable long-term service? I've never seen a bad individual switchover valve. Also possible are internal soldering problems, since it looks as if the thing is built with a PCB inside, and banging on one can open/close some of the bad connections. If I had a third broken unit I'd cut into one to see what was up, but as I'll need two in order to accomplish my plan I'd better not risk damaging one of these further.
While I was at it I disconnected the amplifier connection to the radio. I told Jill to drive with it on (but of course non-functional) for sufficient time to prove whether or not the intermittent nasty noise was coming from the head unit (now isolated) or the amplifiers.
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Pins 4, 5, 6 & 7 (Center, Diverter and both Defrosts) were open and/or intermittent on the original valve block. Pins 1 & 5 (Short Fresh and Long Defrost) were open on the junkyard unit. If I install the junkyard unit, and flange up valves 2 & 3 from the original in place of 1 & 5, that should get it functioning again with the minimum amount of work. (I picked 2 & 3 specifically because they were both good in both valve blocks, possibly indicative of light use and thus the most likely to last.)
So that's what I did. There was plenty of room to lay the second valve block near the first one so that I didn't need to extend any lines. Careful reassignment of rubber bits from both valve blocks is all that was necessary. That, and a large rubber 'Y' fitting that I also grabbed from the donor car. I teed into the electrical lines and soldered the extra connector onto the required lines going to the original connector, and I corked off the now-unused valves in case they should try to actuate due to vibration, or general cussedness. I got sidetracked at about that time and didn't get a chance to test it, or to button things back up.
ZC93769CPa LM2904 dual op-amp, and a heat-sunk L9307 dual driver (the L9309's big brother), probably for the monovalve and the auxiliary coolant pump motor. On the X2 (input) side of the panel there are two 74HC4051 8-input analog multiplexers and another L9309. Three transistors and a LM2940T 5 V regulator complete the complement of active devices. There are two thermistors on the board, one near the heat sink and one at the other side. These are probably used differentially to keep tabs on the high-current driver's state. All in all, it looks like a nice little design.
MKCS0006DH
JH8
QLDR9006
Anyway, I put it back in the car and tried it out again. This time I got normal center vent behavior. I'm not a-gonna look too closely at this, just call it fixed. The car went back together pretty easily after that, even the side carpet. We'll see if this makes Jill happy.
At least the AC was working correctly.
I then jacked up the car and had a look underneath. The rear suspension components are dry, and look like they're hooked up. The valve is in good shape, visibly. That's good. There was a missing rubber exhaust hanger on one of the resonators, so I replaced that. I checked and topped off the transmission fluid, I can see that its leak could well be from the pan so I should have what I need for that. Since I was underneath I used the MityVac on the shift modulator. It leaks down, so I'll need a new one of those too. The input shaft of the steering box is really messy, I need a new seal kit for it, too. I saw no significant signs of any other fluid leakage. I put one of the quarts of Royco oil in the suspension tank, it was long past time to get some more oil into the system.
The rear suspension looks 'down'. I really need to address this.
...Jill reported that the car was shimmying quite a bit. I drove it today, and she's right. The tires took quite a 'set' during the two years (or so) that they'd been sitting on the other car. We'll see if they straighten out, or whether they're ruined.
When she got home I checked the air, and the two rears were low. (Didn't get to them this morning, but they looked OK.) I also noticed that the rear was sagging, we left some bags of dog food in the back for weight, and the suspension fluid was all gone. I put in another quart of the Royco, then I went for a test drive. No real change. I did notice sounds of tire rubbing from the RR on left-hand turns, and when I jacked up that side I could see where it had been rubbing on the interior of the wheelwell, trunk side, but it seemed to me that it looked like it was protruding a bit much there. Yanking on the wheel didn't show any obvious looseness. The rear end was raised again, anyhow.
| Qty | Item | Cost |
| 1 | BAS-1253 Harness | $18.99 |
| 1 | 1319-108 Preout cable ( TP ) | $24.99 |
| Subtotal: | $43.98 | |
| Shipping and handling: | $12.00 | |
| Total: | $55.98 |
I also stopped at the U-Pull and got two wiper blade assemblies from a 126. Sadly, it didn't have the right kind of seat belt.
Schwab was deserted, they swapped my tire immediately, no waiting. No charge either, since I didn't bother getting it balanced. (Not yet, anyway.)
...Still a bit wobbly up front, but I think it's better. Will try another wheel swap tomorrow.
The cables for the Becker came today. One connector block looks fine, but the other I don't quite see how it hooks up. The antenna connector is still wrong, too. I had a closer look behind the faceplate, it appears that there's a CD in it. The navigation maps? Let's hope so!
...Better yet, though not quite perfect. The LF tire was low on air, however, and I stopped at Schwab's for a quick shot of air. I'm going to try swapping it back tomorrow in order to get an A/B/A+B set of wobble data. Then I'll decide what to do, exactly.
I got both new connectors plugged into the Becker. The preamp-out connector was very odd: it's a small connector that plugs into a large sea of pins, but it really can only go in one way. Not something to try to do in the dark!
...Still fine. That fingers the RF tire.
I then got out the Becker 7881 and took it to the car. Just as I thought, the connectors don't match up with what's in the car. That'll be fun.
Regarding the connector mismatch on the pre-out cable, Becker is checking the invoice. The ordered/invoiced part number 1319-108, which matches (partially) the tag on the cable. Its full number is 1319.108-276, and also has Zeichnungsstand 20.10.98, Fertigungsdatum 31/05, and Prüfnummer 973/108 on it. I've also asked for the security code.
...Becker says that the wrong pre-out cable was ordered or shipped, and to send it back and they'll substitute the correct one, part number BAS-1185.640, which has the three-pin plug on it. They also state that the decoding will be $20. Great. I mailed back the incorrect cable today. $1.56 that cost me. I asked them to bill me for the code. The costs (in pain and dollars) are mounting up!
The stereo cable came today, and looks to be the correct one. The paperwork had BAS-1185-640 scrawled on it, and the part itself reads: 5000-469, and also has Zeichnungsstand 15.01.96, Fertigungsdatum 39/06, and Prüfnummer 5000-469c on it. "Made in Tschechische Republik". There was no sign of the asked-for security code.
I moved to the other side and took off the bad wheel and put it (and the last replacement) in the Frankenheap to take in for the swap. I grabbed Daniel and we went in, they were able to do it right away. No charge for this one, either. When we returned home I put it on the car and let it down. Ready for action again!
MMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMM ← Mpingo (wood) body
= = ========____MM + MM
= = ======== MM___, | MM
↑ MMMMMMMMMMMMMM| | MM
| MMMMMMMMMMMMMM| | MM
| .
| Antenna . ,_____,
Plug . | V | ← Protruding antenna jack
. | | |
- - ---------------- - -
7881 Radio
The two 14-gauge wires are pinched against the antenna plug by the
holes in the wood; the shield wire is similarly pinched against the
antenna jack shell. The signal wire plunges freely into the antenna
jack, some glue in the open space helps keep it oriented.
Sounds like a plan, I wonder if it would work? Six precision holes using what are essentially hand tools is not really a recipe for success. This'd sure be a lot easier if I just had a female Motorola antenna socket that I could use, I wonder if the junkpile has one? I should look harder.
The metal piece unscrewed easily from the Delco, and I cut the wires going to the socket. I ground off the metal bracket, the socket that remained snapped easily into the plastic clip on the back of the Traffic Pro. I cut a piece of 10-gauge copper wire to serve as the center plug, and a piece of 14-gauge copper to wrap around the outer shell. (10-gauge is what fit snugly into the center socket.) I soldered both to the antenna socket and attached the assembly to the radio. Looks cruddy, but is secure enough.
I slipped the unit into the car and hooked up the blue antenna control lead, which needed a crimp-on spade lug and some electrical tape, and turned it on. Re-entering the code I could then run the radio, which identified the stations by call sign and started playing. I'm only getting sound out on the left front speaker, but I'll dig into that later. I tried a CD and it seemed OK, and a whack at the navigation system showed it reading the CD and then asking me to select a destination. I removed the original Becker retaining clips and put them in the radio box in the trunk, and pushed the unit most of the way home in the dash. I think it's going to work.
Let's hope Jill likes this thing, it was certainly enough expense and trouble!
| HC (PPM) | CO | CO+ CO2 | O2 | RPM | |
| Cruise Limit: | 150 | 1% | 6% | N/A | N/A |
| Cruise Emissions: | 51 | 0.1% | 15.3% | 0.09% | N/A |
| Cruise Result: | PASS | PASS | N/A | N/A | N/A |
| Idle Limit: | 220 | 1.2% | 6% | N/A | N/A |
| Idle Emissions: | 20 | 0% | 12.2% | 3.62% | 780 |
| Idle Result: | PASS | PASS | N/A | N/A | N/A |
I have no idea what the CO+CO2 'limit' is supposed to mean given that CO2 (along with H2O) is the ideal engine exhaust. Engine too big? Lame.
I removed the N30 (?) from the car. Two spring clips held the unit into its nest, and one rather strong spring clip held the connector onto the unit. (The connector does look just like the CIS-E controller I found in the 380 SL.) I took a plastic bag and tied the connector in it, for protection, as this may well be a 'permanent' condition.
The controller bears the following labels on a blue sticker:
| (B) | BOSCH | 0 265 101 018 (085) | |
| Made in Germany | |||
| (MB) | 005 545 21 32 | 06424473 |
The plastic cover shell was held on with four self-tapping coarse thread Philips-head screws, and had a rubber gasket between it and the pot-metal casting that carries the 35-pin connector and the circuit board. The circuit board had been dipped in a very soft clear conformal coating, much like RTV. It seems like it might scrub off mechanically, if necessary. There were two big 40-pin DIP AMS-brand (?) IC's on it, they looked identical and were labeled:
| 8950GAL |
| BB 33 208 |
| C14445 |
| AUSTRIA |
There was also a 16-pin DIP: Siemens 30008, 9002, and a 21-pin ZIP IC clamped to the casting. (Markings hidden by the clamp.) There were two hybrid modules mounted at right angles to the main board, and three large inductor-fed power transistors clamped to the casting, markings also obscured by the clamps. There were two aluminum electrolytic capacitors and a tantalum, and a 4.194304 MHz crystal. There were seven diodes of various sorts, and the usual crowd of resistors and capacitors filling out the complement. All date codes are '89 or '90.
The solder joints didn't look all that bad, but as I've found out plenty of times already that doesn't necessarily mean much. However, today I'm not trying to repair it, only disable it. I put the cover back on and bagged the controller (for protection of the now-exposed connector) and put it back in its nest for safekeeping.
I topped off the windshield washer fluid with water and checked the brake fluid level, which was OK.
I really need to look into that.
Jill's been noting that the engine temperature is too high, and that the power steering is groaning again. I checked the steering fluid, and it was low. That was easy to correct. When she got back from an errand I checked the radiator, and it was pretty cool behind the cooling fan, yet fairly hot along the sides. Not a good sign. I used the hose to spray it out, hoping to remove any gunk that was cutting the airflow. (There was a lot of mud along the bottom.) Better that than reduced fluid flow, which is what I most suspect. We'll see if it's any better after this. I may need to do an acid flush.
I did this, but I first had to replenish the hydraulic fluid in the jack in order to get the full height out of it. (I used power steering fluid.) Once up and on jack stands I removed the fan and drained the coolant. I was only able to get a gallon out of it. That doesn't bode well for reusing it, there's at least another gallon trapped in there. I dug out the bag of flushing thermostats and swapped in the correct one.
I also had a look at the transmission leak. It really looks like it could be the pan that's leaking, so I should be able to fix it. I already have a new filter and gasket kit, I just need to check the pan's flatness. Overtightening the bolts bends the pan, but it can be bent back. I'll use the saw table (ground cast-iron) as a flatness gauge.
I tested the thermostat in a Pyrex cup using boiling water and a meat thermometer. I filled the cup with hot water and then added boiling water to bring the temperature up. I'd spill out water to cut the thermal mass, raising the proportion of boiling water to not as I went. The thermostat started to crack open at around 77 °C (the thermostat was marked 80 °C), by about 90 °C it looked pretty far open: maybe 1/4" or so. When left to cool on its own it was pretty much closed again by 77 °C.
I dug in the garage until I found the 38-oz (2.5#) bags of powdered citric acid that I'd bought with a neighbor. (We'd split an order.) I don't remember what I paid, but I think it was about $5 a bag. I ran out of time to perform the acid flush today, but I gathered everything I'll need for tomorrow. (Or perhaps even tonight.)
...Yes, tonight. I followed the procedure I used before on the SDL. (This is essentially Job 20-015 in the service manual.) I let it idle about a half an hour with the acid sealed inside, that gave it about 15 minutes at operating temperature. While it was idling (with the heater on full) I kept feeling the back of the radiator. Eventually it got to a more-or-less even temperature, which was not the case initially. Hard to say whether or not that's a significant test, what with no airflow through it. While it was hot I started putting PB Blaster on the transmission cooler fittings.
I also let the car idle during the water flush to remove the hot acid. I pushed water into the filler neck and let it perk out of the special upper radiator flushing hose's fitting. When the hot water coming out no longer tasted sour I shut off the engine, then let it flush more until the water coming out was cool. The whole procedure took about half an hour. That should have gotten most of it. While I waited I dug out the spare monovalve I'd gotten at the junkyard some time ago and checked its rubber bits. It looked good. Next session I'll pull the car's monovalve insert and see how it looks, and swap inserts if the junkyard one looks better.
I tried to remove the suspension pump, but two of the 5mm Allen bolt heads stripped out. (Fucking things, whomever thought that those pieces of shit would be better than regular 10mm hex bolt heads needs a blanket party.) One of the bolts is a short one (of two) that only holds the head to the pump body, the other is a long one (of four) that's holding the pump (head and all) to the block. I'm not sure what I'm going to do there. When I do get those bolts out, all of them will need replacing.
...After I got home from work I tried again, this time using some hammer-in left-hand twist bolt extracters. One of them was just the right size to hammer tightly into the dead Allen sockets, and they cracked loose and came right out when I turned the wrench. So I'm back on track again, I'll just need new bolts for sure. (I knew this already!) I'll get those tomorrow.
I then reinstalled the thermostat, there was a lot of gray sludge behind the flushing thermostat. Not sure what's up with that, but I wiped it out. I then drained the transmission pan. I loosened its six retaining bolts, and some of them were very tight. No wonder it leaks. I'll tackle this next. So far things are on schedule, which means I have all of tomorrow to finish it!
...At lunch I bought the new M6-1×60 and M6-1×20 bolts at the hardware store. They only had lengths that were a bit too short or a bit too long, so I went with long. About $6 for all six bolts, highway robbery!
...When I got home I installed them, using some flat washers from my Harbor Freight hardware assortment. They all fit well in spite of being a bit longer than before. The suspension pump's back in place now, let's hope it worked.
I then moved on to the transmission pan. I scrubbed off the worst of the dirt, then removed the pan. It was filthy, I tried it first in the solvent tank, which wasn't working well, and then I got smart: I got out the pressure washer, which made short work of the mess. There was a gray-black film on the inside of the pan, the washer made short work of that too. After I dried the pan somewhat I took it to the wood shaper to use its cast-iron table as a flatness gauge. It was difficult to do because of the pan's 'ears', but I could see that the pan rocked in the middle. I took a straight-edge out to the transmission and its gasket surface was flat, so the pan was definitely deformed, obviously letting the back end lift away from its mating surface and thus leaking. In fact, the highest point on the pan had cut entirely through the gasket, though it was interesting that this wasn't the point that was leaking. I used a hammer and a rubber mallet to bang away on the pan until I got its sealing surface nearly flat. I test-fit it to the transmission, sans gasket, and it didn't rock anymore, so I cleaned up the mating surfaces and attached the gasket to the pan. I then removed the filter, and installed the new one. (At 222150 miles.) The old filter had the gray film on its upper surface too. I looked at the vacuum modulator as it really needs replacement, but I don't have another one, nor do I see exactly how to replace it. The job looks tricky, it might be that the valve body has to be removed. Another time! I reinstalled the pan, being careful not to overtighten the bolts. I made sure to tighten them in stages, to keep the pan flat.
Time for breakfast!
...Tummy full, I'm ready to recomission the car! I emptied the oil drain pan into an empty gallon oil jug, paying attention to the amount. About three quarts. That told me to put in four quarts of ATF, as a start anyway. I poured the salvaged coolant back into the car and topped it off with water. (A gallon of Zerex G-05 will be put in later.) I put another quart of the Royco 756 in the suspension tank. (There's only one can left on the shelf, then things start to get more expensive. I sure hope this takes care of that leak.) Ready to go? I started the car and watched it idle for awhile, looking for leaks. Things looked good, no dripping.
I then lowered the car and took it for a spin, it passed. Seemed to drive as before, and I didn't see any dripping. The coolant level had dropped a bit so I put in a little more water. Ready for the road! I put another quart of ATF in the trunk, in case we need to add more on the road. (Getting that level right is very difficult for me.) Then I cleaned up the mess I'd made.
...After a test drive I found some seepage of suspension fluid on the bottom of the pump. It's probably the head gasket, but might be one of the fittings. I lack the time to do anything about it, however.
The hot engine idle speed is much too high, around 1500 RPM. Not as high as it goes when you unplug the idle actuator, so it's at least trying to work a little, but it's definitely not right. Perhaps it is unhappy about the hot coolant and acid fountains it was sitting under during the flushing? I need to look at it.
Well, why not today? I popped the hood and pulled off the air cleaner for easier access. This thing sure seems light...WTF??? There's no air filter in it! Never has been, I can't believe I never noticed this before. What an idiot, and we live on a gravel road! The air horn was caked with oily dirt, as was the air metering plate. I used carb cleaner to remove all the dirt, then decided to go for it and so I removed the backfire stop and the air plate itself. I cleaned everything I could, as far down into the air chamber as I could reach with the solvent and a rag. I got a lot of it out, certainly the upper reaches were clean. I put the air plate back, and using a magnet (for grip) and a wrench got it centered so that it didn't rub anymore through its travels. It had seemed a bit rough before I started the cleaning, perhaps this will help the rough idle? I know the plate is sensitive at the idle positions. If it drags at all the idle mixture will be wrong.
I went to the garage and retrieved the surplus air cleaner housing I'd gotten for Jill's 560 SL, it had an air filter still in it. After cleaning the dirt out of the car's housing I put the used filter in it, it looked clean enough. (Better than nothing!) The spare housing also had the fitting/filter for the smog pump that this car was missing, so I moved that over too. That'll be better.
Anyway, on to the official project. I looked at the idle air valve, and when I tested it with a battery charger it worked perfectly. The Shoe-Goo'd rubber pipe was split again, that was probably the problem. I cleaned it and re-Goo'd it, this time cutting a ring of inner tube rubber to slip around the outside of the repair. That'll cork off any future splits that develop. I really should get a new rubber pipe, it can't be that much money!
I also tried re-centering the air plate, Jill reports that it now has trouble starting, it wants to die unless she gooses it. If this drags at all on the close-fit walls there will be problems at idle.
According to the ETM (page 208), the Idle Speed control unit (N8) is "Front passenger footwell, behind right kick panel." The photograph, page 229 Figure 1, shows it next to the airbag switching power supply and capacitor block.
(MB) 006 545 85 32and ink-stamped with 501 and 19/90. It has 11 pins in a 12-pin site, labeled (facing the pins):
Leerlaufdrehzahrlregelung LR 0005
Idle Speed Control 8 Zyl.
412.214/001/004 12V
/ /
+---------------------------+
| -31 15 87B C KL V |
| |
| O O O O O O |
| * * |
| O O O O O |
| |
| 50* TD 87A LL TF |/
+---------------------------+
The black plastic shell popped off of the pin carrier with a bit of careful prying. Inside it's considerably different than the usual vintage electronics I've come to expect in these cars. Progress, I guess! There's a daughter card soldered on standoffs to the main card. The daughter card is all surface-mount and conformally-coated, and single-sided like a hybrid module, and has an exposed IC die clear-potted to the board along with two LM2902 quad op-amps and a 4.194304 MHz crystal. There are also surface-mount resistors, capacitors, diodes, and transistors. It looks to be in great condition, which is good because this kind of thing is next to non-repairable. The 'main' board is traditional through-hole construction, and has relatively few parts: four diodes, some resistors, two power resistors, three small electrolytic capacitors, and two small power transistors (BD437 and BD438, a NPN/PNP pair). This board is not coated, and some of the solder joints looked a little suspect, so I resoldered it.
It was raining today anyway (not convertible weather), so I threw the IR temperature gear in the car for testing the cooling system temperatures later. I put the 'repaired' idle controller back and drove it to work.
The Fluke IR probe has been flakey for some time now, and it wasn't the battery. I opened it up to have a look. I found a solder whisker shorting across the output terminals, I think that could explain its sensitivity to the position of the battery and its wiring. I cleaned off the whisker with a soldering iron, set the probe to Centigrade, and put it all back together. The probe end is pretty elaborate. It looks like it might have an emitter and a sensor, and there's a large coil as part of the head assembly.
...Idle speed was unchanged, about 1400 RPM when warm and in neutral. Only a little above normal when in gear and stopped, but the car's pulling against the brakes more than it should, and it doesn't really slow down when you let off the gas—you need the brakes more than you should. It really must be the actuator and its hot acid bath, but it's an odd failure mode since it seems to work right on the bench. I really need to find my spare so I can try it in its place. I don't want to buy a new one on speculation, as they're fairly expensive.
Engine temperature was rock-solid right where it needed to be, but it was only about 60 °F today. I felt the radiator after I stopped and it had an even temperature gradient, even behind the fan. That's an improvement, at least.