Progress
 

Nice ! .

I'd love to read how you tweaked the injectors pop pressure .

I just installed a fresh set of balanced injectors and if FeEx ever stops messing 'round I expect my new delivery valves have arrived from Germany....

I don't have nailing issues, just a soft miss that comes and goes and minor over fueling smoke with it .

Tweaking the injector pop pressures isn't difficult, but it is time consuming. You have to have access to a pop tester (mine is one from a certain "source") and an assortment of shims for the spring. You simply open up the injector and swap out the shim until you get the pop pressure where you want it, then you perform a few tests to make sure that the pintle "chatters" and doesn't leak. There are writeups here, on rival forums, and videos on the Internet how to do it. Replacing nozzles, cleaning the injector bodies, and calibrating the pop pressures on 6 injectors took me right at 2 hours. Would have been less than that, but one of the injectors was a real PITA to dial in and took about 5 or 6 attempts before I was happy with its pop pressure.

Injector Service
 

Thanx ;

I do have a pop tester I bought new after a lister here ripped me off for a home made one .

I use it to check all my used injectors but don't really think I have the knowledge to be servicing them .

You have the hard part done then. If you have access to a bench vice, take the injector apart. It comes apart in halves. Upper half will have the shim, spring, and tappet. Lower half will have the sealing disk and the nozzle/pintle assembly.

Soak the whole thing in solvent and make sure it is VERY clean. Use a piece of glass (I use a piece from a picture frame) and lay down a sheet of 2000 or 4000 grit sandpaper. Dribble on some diesel fuel for lubricant and polish the face of the upper half of the injector holder, both faces of the sealing disk, and the upper face of the injector nozzle (the part that seals against the sealing disk). Clean everything very well in clean solvent. Pull out and let dry, then drop everything into clean diesel fuel.

Hold the upper half of the injector holder upside down (so the part the hard line screws into is pointing at the floor). Drop in your shim(s), spring, and tappet. Lay on the sealing disk, then lay down the new nozzle (or your cleaned old one) and thread on the lower injector half by hand. Clamp in a vice upside down and torque to 70NM.

Now go out and test your pop pressure. If it isn't where you want it, disassemble and add or remove shims above the spring. Reassemble and re-test. You don't need to re-polish the sealing parts when doing this.

Once your pop pressure is where you want it, check the spray pattern. It should have a nice even cone. You shouldn't see one side spraying heavier than the other, spraying off to one side, or spraying in a straight/squirt-gun pattern.

If the pattern is good, move on to chatter. Give long constant strokes just at the pop pressure. The injector should be pulsing on and off as you pump the lever. If you go too fast, you'll get a constant spray. If you time it just right, you'll get it to "sing", sort of a very high pitched whine as the injector rapidly pops. If the injector doesn't chatter, or if it pops and continues to spray without resetting, it likely is binding up in its bore.

Assuming the chatter was good, slowly build pressure in the pop tester until you get just to the pop pressure. Hold that pressure with the lever and check the tip. If it starts to "pee" you likely need to disassemble the injector and clean the holder. Sometimes they will just barely weep, then pop. That's fine. This is a mechanical device, they aren't perfect.

Relieve pressure, then pump up ~15-20bar below your pop pressure and maintain that pressure. On a turbo engine, that's ~1600PSI. Count to 10. You should have no drops coming off the tip of the injector.

Last test. Make sure the relief valve is firmly tightened on your pop tester, then pump the lever until the injector pops, then allow pressure to naturally decay. If it drops below 1600PSI in ~10 seconds, the internal leakage is high. You'll need to re-polish the mating surfaces and try again.

Spend your time up front getting the pop pressure dialed in, then worry about the functional parts later. You'll save a ton of time. The process isn't difficult, just time consuming. An anal attention to detail matters. You'll have a decent running and reasonably smooth idling engine if you get the pop pressures +/-50PSI (100PSI between lowest and highest pop) by adjusting shims. You'll get the best results by getting it +/-25PSI (50PSI between lowest and highest pop). The pop pressure influences injection timing, the tighter the tolerance, the tighter the timing will be. This isn't a perfect world, so don't dwell on perfection. 50PSI spread is fine, 25 is better. If you have compression imbalance, you won't notice the 25PSI difference anyway, so use your time wisely!

Injector Service
 

! THANK YOU ! .

I also have an ultrasonic cleaner I use for Motocycle carbys, might be advantageous to use it for cleaning .

As of yet I'm just using my pop tester to see if my old cores are any good, some are, most pop way below 135BAR .

I have no vise, not even a work bench, I work out side under a 20' X 40' tarpaulin ~ good thing I'm in California, eh ? :rolleyes: .

I have saved this detailed explanation for future use and sharing with others .

For now, I still have much to do on my three old W123's but would like to try setting my own pop pressure .

Some years ago I met a *very* nice Dentist who did his own injectors and adjusted a full set for my '77 300CD in his garage, he didn't understand why I was upset that after he'd 'cleaned' my nozzles using old root canal cleaners, they pissed like tiny garden hoses....

Yes, the car ran *much* better but I'm aware of the spray cone :D .

At long last, I have a radio! Finally broke down and bought an aftermarket radio and took the time to pull new wiring to all 4 speakers. I figured that way I could leave the original wiring harness intact if I ever returned to the OEM radio. Took about 4 hours yesterday evening, but worth the effort. New radio sounds good and as a delightful side benefit, the power antenna works! Talk about high-class, now I have working A/C AND a working radio!

Did you buy the metra wiring harness off amazon? It keeps the original harness in place. Also, the kenwood looks great.. They're the only type of radio I'll put in an MB besides Alpine. They look good, pioneers look they belong in a Honda!

So jealous! Can't wait to have radio and an AC up and running in mine, but it's months away, unfortunately. Good job.

I bought the radio from Crutchfield and it came with a harness kit of sorts. It contained an adapter for the power plug and 4 speaker wire adapters, which are pretty useless if you're trying to retain the OEM wiring harness.

I did use the power plug adapter as intended, but pulled 4 new speaker wires and used the 4 speaker wire adapters to plug the original speaker spade plugs into. Wiring to the front speakers was pretty elementary. To get to the rears, I took off the passenger kick panel, door trim, passenger side seatbelt cover, and removed the rear seat so that I could lift the carpeting along the side and run the speaker wire in there. I eventually bundled it with the existing harness when it came up out of the carpet, so it seems like it belongs.

I didn't bother trying to reuse the OEM harness. The fader was toast and I suspect I had a wiring fault somewhere in the right rear speaker wiring. I never did get a conclusive continuity test out of it. Wasn't too bad, the whole job took me about 4 hours, and that included about an hour of fiddling with the rear seat mechanism to add rubber bushings to places and install springs in place of the rubber straps for the hinged cover over the rear seat back.

I had considered Alpine (which is my brand preference), but the expense for just a basic stereo that didn't look like it belonged in a Ricer was ridiculous. The Kenwood fit the bill and was cheap to boot. It does what I want and sounds reasonably good. I'm satisfied with it, and that's really what's important!

I'll tell you - repairing the A/C was worth the blood, sweat, tears, and swearing. The system in this car is seriously good. Very comfortable and very fast. I love how quickly it cools the car off, then ramps the fan down. I've gotten so spoiled by it, that I'm now finding the manual system in the Honda irritating...

I was fine without a radio for a while, but found myself wishing I had a working one more and more. Especially when taking it out on the road. There's only so much diesel rumble and wind noise you can take before it becomes tedious and you find yourself pissed that you keep putting off the radio... Now that I put it in, I keep wondering why I kept putting it off. The radio wasn't expensive and the installation wasn't difficult!

AC Service
 

I was harvesting parts off a 1982 560SEL to - day and some one had removed the dashboard with a crowbar (of course, it had been *perfect* and they destroyed it :mad:) and saw the AC's expansion valve tucked way up against the firewall behind some harness and decided to see just how bad it is to remove ~ wow, not easy .

Your car is coming right along ! .

Getting the expansion valve OUT is the easy part. Getting it back in will send you to the looney bin. Keep in mind, I did mine with the dash still installed. I did learn that I'm more flexible than I thought I was...

Yes ;

I was wondering how to ever get it back in .

I *think* this one was a replacement as it had a sticker with "R134a" on it, and in 1982 R12 was still the norm .

Really enjoying this thread! The Benz Gods owe you one for breathing life into that poor neglected car...

Can I ask where you got the head rebuild done ? I'm also in the Austin area and am looking at getting a rebuild on my 603 head as well.

OM603 Head Repair
 

Me, I used Metric Motors in North Hollywood, Ca. ~ some Russian guys who don't do Mercedes but are never fazed by little things like the pivot pin for the belt tensioner being broken off in the head....

They also did the 1966 Chevy 292 i6 cylinder head I have including bronze valve guides and hardened valve seats, said " why not ? " when I asked if he'd tackle it .

They normally do Subaru WRX heads for the local kiddie ricer-racers, my Son has a WRX and they did good works for him so I figured no hard in asking .

I used a local individual with a machine shop to do the head on mine. He had done several 602 and 603 heads in the past and knew what to look for. Unfortunately he retired at the end of last year. I sent a PM to Nicholas about another possible machine shop in San Antonio, recommended to me by the same guy who did the work on mine.

In other news, the Diseasel got the mixture tuned a bit. Adjusted the ALDA CW about 2.5 turns to get the "coal rolling" under control. In addition to being irritating, the highway fuel economy has been dismal. Doing 75-80mph, I've only been averaging around 18mpg compared to 25mpg or so in city traffic. Since the tuning, I now have ~220 miles on about 1/3 tank of fuel. The same highway driving previously would have me below 1/2 tank. If it does ~25mpg or so on the highway I'll be completely happy.

A/C Update: Still blowing frosty cold. Much appreciated with the hot, humid weather we've been having.

Radio Update: Never going without a radio again. Completely spoiled.

Delivery Valve Update: "See the D/V as source of nailing" thread for full description. Polished the previously nailing D/V's with cerium oxide and oil and swapped them back in Cylinders 1 and 2 on the IP. So far, the nailing hasn't returned. Engine seems to be running fine with them in place.

So the fuel economy numbers are in. 24.1mpg for combination city/highway driving with the A/C cranking out the cold. I'm happy with that.

Installed a new bearing in the electric Aux fan in front of the radiator. Yay! No more banshee!

Perhaps the most interesting development is that the oil consumption issues have all but stopped since adjusting the ALDA. The engine hasn't dripped oil on the floor, and the oil level in the sump hasn't moved. I'm wondering if the engine was running so rich that I was getting fuel dilution issues in the oil. Would explain a great many things. For safety's sake, I see an oil change in my near future.

Incremental Diseasel updates:

Fuel consumption is still down, the car never smokes unless it's wide open at high RPM's. Oil consumption has dropped to the point I'm no longer worried about it. ~500 miles on this oil change and the level has barely dropped below the "MAX" line on the dipstick. The only change has been adjusting the ALDA. I strongly suspect I was dealing with severe fuel dilution issues.

Earlier this week I changed out the expansion valve in the A/C system. The original one kept hanging open. The result was that it would sometimes work and sometimes wouldn't unless you got the RPM up. Lots of gurgling and hissing under the dash as it hunted back and forth before finally sticking open. The new expansion valve has put an end to that behavior and I'm getting 42˚ air on a 96˚ day. I can live with that!

Helping the A/C system out is a new genuine MB monovalve cartridge. The original one had intact seals, but they were very hard compared to the new one. The movement of the plunger is also very rough compared to the new one. Not to mention that now the A/C blows like an icebox without having to fight the heater!

Just this evening I did another polishing job on a nailing delivery valve in Cylinder #5. Was successful in stopping the nailing. So far that's 3 for 3. This fall (when it cools off) I intend to do some IP work and I'll lap all 6 DV's at that time. The IP is leaking oil and needs new seals and I still need to tweak the RPM limit to let the engine rev to the proper limit.

Other than that, it's been business as usual. The SDL has been the "daily driver" for the last couple of weeks and been doing a fine job. Working A/C and a working radio sure make a difference in the creature comfort department.

Delivery Valve Service
 

Glad to hear this! .

I really need to get back to doing AC works, I haven't since 1986 or so .

I may have missed the part about lapping (by hand I assume) the delivery valves ? .

I just bought five new ones and it helped a whole lot .

Been a while since I updated this thread...

The DV polishing can be found in reply 116 in this thread: http://www.peachparts.com/shopforum/diesel-discussion/363700-delivery-valve-internal-leak-cause-nailing-yes-no-maybe.html

It's worth a read for the diesel guys, especially folks who have been chasing down nailing that won't stop and all the "usual suspects" have been checked and serviced.

In other Diseasel-related news, it goes on its first road trip this weekend. It's been running well lately, A/C and radio work, and the fuel economy has risen to normal levels. We'll see how it does in 100 degree temps driving over hills on the interstate at 80-85 for a couple hours each way. It needs a good run and I finally trust it enough to make the trip there and back. Hoping it doesn't let me down.

Road Trip Success!
 

The Diseasel went on its very first long-haul road trip this weekend and boy what a doozy it was. I picked the hottest day in memory to take that poor car for a 2.5 hour drive at 80-85 out west on the Interstate.

The day I drove up it was 108˚F and HOT HOT HOT. I-10 going west has a lot of very long steep hills and west of Gillespie county has a speed limit of 80MPH. Quite the shake-down test for a tired old car.

The trip was completely unremarkable. Car made it without so much as a hiccup. A/C blew ice cold the whole way there and it had no problem keeping pace with traffic even when going up the steepest hills. On the trip going up, it used ~2 cups of oil, about 1/8" down on the dipstick in ~150 miles. This was down markedly from it's normal consumption on fast highway runs in the past. It would use up to a quart or more on a 100 mile trip if doing 75 or better.

Saturday we took it on another fast highway run for another 160 mile trip to go run some errands and do some thrifting. Car didn't use any oil on that trip despite doing the same speeds.

On the trip home, the ride was again uneventful. Car still didn't use any oil on the way home. I'm very happy with that result!

In addition to finally quelling its thirst for oil, my idle shake is also gone. MPG on the trip up was 22mpg, the trip home was 25.5mpg. I attribute some of that to the heat, but the rest to the engine finally working properly. I guess the old belief that these old diesels need to be ridden hard for a long period of time after sitting really is true. It certainly seemed to help this one! I suspect that the hot, hard, long run on the highway finally got the rings hot enough to cook the carbon and other crap out.

Nice car!

Curious if you addressed the clear coat, or just sanded and buffed what was there to work with. I'm not sure how long the buffing will hold up on the base color coat.

No, I haven't done anything with the failing clear coat on the hood. As the clear coat fails, it is slowly peeling off the hood and it looks much better than it did. I'm not intending to do anything to correct it since I'm intending on having the car repainted at some point in the future.

High temperature for a cruise at 80mph. All my diesels never run over 85C on the highway. Check your fan clutch.

You're also not running at 108˚F ambient temp with the A/C blasting. It never runs that hot except for that one trip. As soon as the temp got back down below 105˚ outside, it dropped right back down to 85˚ where it always runs.

Fan clutch is fine btw. At RPM's these cars run doing 80, they're slipping anyway, as designed.

OM603 belt Question
 

i need a diagram of the 1987 300SDL's OM603 serpentine belt's routing please .

i tried search and didn't find it .

TIA,

The belt routing on the OM603 is truly bizzarre. Very confusing and not at all intuitive. Get it right and it works great. Get it wrong and the belt doesn't fit!

Follow this link to a posting on this forum showing the correct belt routing: http://www.peachparts.com/shopforum/1111680-post1.html

OM603 belt path
 

thank you ! .

How did you clean your gauge faces in this post?

I replaced the gauge pod with a good used one I sourced on eBay for cheap. Came from a 300SE and the gauges went to another member of this forum.

The gauge faces got cleaned with denatured alcohol and a paintbrush. I soaked them down, waited, then gently scrubbed with the paint brush (and I mean artist's paintbrush). Took a while to clean, but took off the "cancer spots" without taking off the paint.

Been a while since I've updated this thread.

A/C is still blowing ice cold. I washed out the evaporator coil first part of July and it made a HUGE difference in how the A/C performs. It was adequate before, but now it's ultra-effective. Even the hottest days, I can cruise around in air conditioned splendor. So lovely!

Recently, the tappets have been getting noisy despite plenty of oil flow, so the time was right for new tappets. I put in 12 new INA tappets this evening and it's so nice to have that shaking idle gone! No more tappet rattle and the smoke under acceleration is markedly improved. Another unintended side-effect is a NOTICEABLE improvement in power. I'd not have expected that, but if the tappets were collapsing, I guess that's explainable! One of those "you have to experience it to believe it" things.

While doing the tappets, I decided to check the valve guide seals to see if they were in the correct locations. The FSM shows green as Exhaust and brown/black as Intake. Unfortunately my car has them reversed which could explain the high oil consumption. I have a thread running in the Diesel Discussion forum on the topic. It may become a fall project to correct the valve guide seals.

A project that WILL take place this fall is tuning the injection pump. I intend to raise the RPM limit to the correct 5150 RPM from the 4500RPM it currently has from the 3.5L engine. I also intend to trim the fuel back slightly to help with the coal rolling under hard acceleration.

Otherwise, the car has largely been my daily driver all summer. Surprisingly to me, it's been an extremely reliable car. I'm used to the SL that seems to have something go wrong every time I take it out!

Progress !
 

Thanx for the update .

It sounds like things are falling into place .

New valve guide seals dramatically cut the oil consumption issues and the injection pump tuning made a profound difference in the coal-rolling. No more black smoke! It will be interesting to see what the fuel consumption is like post adjustment.

I also took the time to re-seal the ALDA. A 10mm x 15mm x 2.5mm O-ring will do the shaft and a 52mm x 57mm x 2.5mm O-ring will do the peripheral seal. Having a properly working (non-leaking) ALDA makes a big difference to how the car drives. The power comes on nice and smooth instead of being gutless to 2000 RPM then suddenly having power. Such an improvement around town!

Minor update: Got rid of the oil smell in the cabin. Turns it was just the oil on the block burning off. Rinsed that off with some degreaser and for the first time since owning the car, no smell of exhaust or oil in the cabin. Joy of joys!

Oil Stink / Mess
 

Please go look for Rich's 'Best Degreaser On The Planet' thread ~ it's @ Sams Club and really is amazing and cheap too @ $6 (IIRC) the bottle ~ I dilute it a bit and use a hand spray bottle and a soft brush ~ my poor old grimy Coupe's engine bay and undercarriage haven't looked this nice since 1987 :P .

I commented in that thread many months ago with what my preferred degreaser is. I use a product called "Oil Eater" from Amazon. Cheap, comes in a 5 gallon pail so it lasts forever, and out of all the various products I've used over the years (including industrial products) it works the best by a wide margin. A 4:1 mix of Water:Degreaser will make oil grime simply melt off the engine. Spray on, wait a few minutes, rinse off. Spotless. For a completely grime-free finish, repeat and you'll have a shiny engine with no goop leftover. I'm not that anal, so I do it once and move on with life. My biggest appreciation is that the Oil-Eater stuff doesn't discolor aluminum like the purple cleaners do. BIG PLUS in my book!

Irritating update - had to do some A/C work today. I noticed over the last few days that the A/C hasn't been cooling as well as it should and noticed yesterday that the Aux fan wasn't kicking on at low speeds anymore. I had the hood up today to adjust the Bowden cable and heard a hissing noise. Was the fan cycling switch on the receiver dryer. Wasn't leaking from the brass part, oh no, it was leaking from the plastic body. Behr branded part too. Took the refrigerant down to about 5 PSI and quickly swapped the switch for a spare ACM I had. Topped back up and back to cooling like a pro. I'm more than just a little irritated that the Behr part failed like it did, but at least I had a replacement part and got it back to blowing frost.

Another Great Degreaser
 

Thanx ! .

I did some fine tuning to the IP yesterday to follow up from last weekend's adjustments. Turned the 2f screw 1/3 turn CCW to give it slightly more fuel and turned 2m 1/2 turn CW to finish raising the RPM limit. The result is a car that's got some balls! It's seriously quick and still no smoke so I'm a happy camper.

Found some diesel this morning too, so I filled up and ran the fuel economy numbers. Did 135 miles in 5.8 gallons, which brings us to 23.77mpg. With all of the driving being in town or romping on back roads, that's really not bad considering I was 18-20mpg before the adjustment and driving carefully!

Today I decided to tackle the horrible rear seat. I'm not ready to shell out decent money for a new cover when I still have so many other things to do to the car first and I've been unsuccessful locating a replacement cover that people don't want a truly stupid sum of money for. Had a guy on this forum (who shall remain nameless) try to sell me a cover with a ripped bottom for $500 claiming it was a bargain. Sorry pal, I can get a NEW cover made for that without tears! No sale, Charlie.

The gaping hole in the top of the cover and the poor condition of the leather led me to try something else. I decided to get a cheap blanket and stretch it onto the seat frame to cover the existing cover. I'd lose the fold-out arm rest doing it this way, but since only the dogs ever ride back there it isn't a big deal. To date nobody who'd ridden back there has used the arm rest!

So check out the photos below to see what I started with. The leather is completely dry-rotted to the point that touching it turns it to dust. Simply no saving it so something had to be done.

Purists Look Away...
 

For the purists out there, look away now! Seriously! You've been warned!

Fair warning out of the way, I had a "helper" for my project. Not sure how much he helped or if taking a nap is really considered "helping", but he thought he did a good job anyway.

I firmly stretched the blanket in place and wove 1/2" poplar dowel rods in the seat frame to attach the blanket to. 3/8" construction staples finished the job and I wound up with what you see below.

Certainly not "factory new", but 98% better than a ratty old seat cover with a giant gaping hole in plain view. Not bad for a budget of under $8.

Seats & IP Tweaking
 

I wish you had images to explain what and where those two screws are....

The seat looks much better ~ I'm sure the Supervisor you pictured will enjoy it better than the old leather .

Good Supervision is essential ! .Attachment 144097

I hear you about used seat covers being sold for stupid $ ~ I had some @$$hat try to sell me a ripped cover for $250, he'd bought a regular old $30 used seat at the junk yard and thought I'd be making his next boat payment by selling me the worthless cover for more $ than a new one....

WRONG .

Some folks let their greed overcome their common sense, more's the pity .

More information on the IP tuning can be found in the thread I have running. Specifically page 4 has all the info you want. Be advised, the SDL uses the "M" pump which is a different critter from the OM617's "MW" pump. http://www.peachparts.com/shopforum/diesel-performance-tuning/386114-help-tuning-603-ip-4.html

Today's task was a continuation of the "De-Pimp My Ride" saga and entailed trying to make the paint look more presentable. I've noticed that the paint hasn't been beading water and was disappointed to note that the Meguiar's wax I used didn't even last 8 months. The rest of that tin went in the trash and I spent the day dolling up the rest of the car.

I started out by wet-sanding the hood in an attempt to even out the paint and smooth the transition where the clear coat is peeling. Took the compound to it afterwards, then waxed the whole car. It's always a surprise to see how well that car will clean up! Imagine if it had wheels that weren't awful, it'd look downright presentable!

RED LETTER DAY!!!
 

Working cruise control! What a luxury!

Cruise Control
 

Oddly enough the C.C. on my '84 300CD with 400,000 + miles still works like a charm.....

You car is looking good .

I suspect that this car has had something *BAD* happen to the electric system in the past like a battery hooked up backwards or a runaway voltage regulator or something since I've found faults with every electronic item in the car. Only the EDS computer and ABS computer seem to function properly, anything else solid-state has had issues. The CC was the final thing needing to be fixed.

After trying to repair the amp board myself, I sent it off to Kris (JamesDean on this forum). There was something really squirrely going on with that board, so he kindly accepted it as a core and sent out a rebuilt unit. Much appreciation! I do recommend his work for electronics repair, if anyone cares.

Because I felt like it, I ran fuel economy numbers today. 76.0 miles on 2.862 gallons of diesel for an economy of 26.55mpg. Pretty impressive! No smoke, plenty of power, and now decent fuel economy. It's all coming together...

To rule out a fluke fuel economy reading when I recorded that 26.55mpg, I've run it again. This time I got 79.4 miles on 3.122 gallons of fuel which gives 25.43mpg so it wasn't a fluke. I've been having a bit more fun with the throttle this time around, so I'm fine with a deviation of ~1mpg. I'm just happy to see the fuel economy improved to where it should be without any smoke!

Speaking of smoke, the oil burning smoke has reduced a bit more. Not sure if the thicker oil is helping seal up leaks, or maybe the rings are finally seating some without diesel washing past them. Who knows. I have a bit over 650 miles on this oil change and so far I haven't added any oil other than what spilled out during the IP tuning (I measured what came out (10 ounces) and put that much back in). So far the oil level is still at the "MAX" line on the dipstick, so it looks like the excessive oil consumption is in check as well. It still burns enough to smell on the exhaust, but no more blue cloud.

I finally broke down and installed new speakers front and rear. What a difference! The 1986 speakers that were in there weren't terrible, but they certainly weren't all that great. The biggest annoyance was the "farting" when the volume was turned up on the highway. Even with the bass turned down (not that there was any bass to begin with) it still had a nasty habit of spitting and farting with the volume up loud enough to be comfortable at highway speeds. Not anymore! Now I can get a decent volume out of the stereo AND there's actually a bit of bass. Such a luxury!

I've been chasing down anomolous fuel economy readings lately. I've always had issues with highway fuel economy being terrible, but now the city mpg's were taking a crap too, but only when the trip odometer went over 100 miles. Turns out the odometer stepper motor was at fault. It gets sloppy in its mounting and doesn't reliably engage the gears anymore, the fix is an O-ring in the end bearing to stop it moving around. Seems to have worked! You can read more about it here: http://www.peachparts.com/shopforum/diesel-discussion/388727-odometers-not-agreeing.html

This latest tank had 141.8 miles on it, and I did 24.09mpg with mixed driving. Puts me right back where it should be ~25mpg +/-1mpg

I had the car on the interstate this evening for the first time since retuning the injection pump. What a car on the road! Now it holds speed just fine up the hills, no more gutless howling with a cloud of black smoke trying to climb the hills. Smooth, quiet, and effortless. So refined! With the CC working, A/C blasting, and radio thumping it was quite a relaxing drive, no wonder people love these cars.

A few updates, and a new 3rd brake light
 

Fuel economy is still good. Now with a properly working odometer, the fuel economy has remained consistent with longer fillup intervals. I did 275 miles on this past fillup and did 23.5mpg with about 98% city driving with A/C.

The latest project has been installing a new 3rd brake light assembly. The bulb burned out in the original which was extremely brittle. When I tried to open it to replace the bulb, the entire thing shattered, including the plastic riser that the fixture sits on. Considering that the originals are ALL fragile like that, I elected to order brand new parts and hopefully get another 30 years out of it.

I bought my parts from the dealership, which turned out to be the cheapest way to go, even when including sales tax. The parts took nearly a month to come in, I assume they came from across the pond, or maybe the dealer was just slow, who knows.

The part numbers for anyone interested are:
Lamp assembly: 001-820-41-56-7007
Cover assembly (riser): 126-820-01-82-7007

The EPC gives different 4 digit codes for various other colors, however only the 7007 (black) is still available. I was considering painting the brake light assembly if I didn't like the black, but I don't mind it, so black it will stay until I overhaul the rear parcel shelf.

Some pictures of the process are below. To get around the irritating "bulb out" indicator on the dash, I made a "dark bulb" out of a light bulb wrapped in tin foil. Be aware that this is an instant safety inspection fail (ask me how I know).

The new assembly comes in 2 pieces as I said above. The Lamp Assembly comes with a new bulb already installed, saves the need to open it up to install one. The "speed nuts" I show in the photo are salvaged from the original. They were still on the metal tray under the parcel shelf.

To replace the assembly, the parcel shelf has to come out. To do that, remove the rear seat, the little "flipper" cover that covers the gap between the seat back and the parcel shelf, the speaker covers, speakers, and the 2 latches for the first aid kit lids. Once those parts are removed from the car, the parcel shelf slides towards the front of the car and comes right out. I saw several guides that say to remove the C pillar covers, but I didn't find that part necessary. The fit is pretty tight, but working side to side it will just slide out.

The "cover" (riser) part attaches to the parcel shelf as I show with the "speed nuts". They are very tight, I found it was easiest to use a 5/16" nut driver and wobble it in a circle to work them down on the plastic pegs. When finished, the cover (riser) should be nice and tight against the parcel shelf. If it is still wobbly, you need to get the speed nuts tighter. There are only speed nuts on the 2 pegs in the "slotted" holes in the parcel shelf.