The "Diseasel" - '86 300SDL - Page 4 - PeachParts Mercedes-Benz Forum

Diseasel300 · #46 04-13-2017, 12:50 PM

All in due time. This is a hobby/project car, so it slowly gets the bugs worked out. Once the mechanical side of things are to my satisfaction I'll turn attention to the cosmetics. No point in having fresh paint if it's just going to get scratched up and greasy from working in the engine compartment! Body work is the very last thing that will happen to this car. There are a few nicks and dings here and there, but the biggies are the hood and trunk lid. It doesn't bother me, and that's what's important.

vwnate1 · #47 04-13-2017, 10:55 PM

Understood ~

My beloved 300CD's original paint is getting pretty poor plus nicks and dings and the @$$#ole neighbors drunken lout buddies side swiped it from stern to stem a couple years ago, if I ever get the smoking under control I'll see bout getting it re sprayed, I can hardly wait .

Diseasel300 · #48 04-14-2017, 11:05 PM

The past couple of days have been busy. Good news is that the A/C is now working! GLORIOUS cold air! Went for a drive this afternoon to test it out and it seems to have no problem keeping it like a meat locker in there. Read all about the A/C resurrection here: Resurrecting a dead A/C - Where to start?

I also repaired the MOST IMPORTANT feature on the car - headlight wipers. Because what's the point of driving an ostentatious car if the uppity wipers don't work? Sourced an eBay wiper motor for the right hand side to replace the shorted motor that was in there. Installed a new washer check valve and cleared all of the "goop" out of the squirters and lines. Spent some time with a crow's foot and got the motors adjusted so that the wiper arms come to rest just a hair above the glass bump on the headlight lens. Now they sit horizontal when shut off instead of at weird angles like you always see them. OCD is a dangerous thing...

Tomorrow it gets a much needed bath!

Diseasel300 · #49 04-16-2017, 12:54 AM

Milestone achieved - Odometer clicked past 175K this evening. Put about 250 miles on the car today A/C blowing frosty the whole time. Wonderful.

I should really get the form filled out to get the 250,000Km badge for this car, it's well past that point, "only" another 135K or so to get to 500,000Km. Considering it took me 6 years to put 108K on my daily-driver Civic, it may be a while...

Diseasel300 · #50 04-28-2017, 12:21 AM

More recent developments in the life of the Diseasel. The dome light went tits up and I'm pretty certain it cooked the seatbelt relay in the process. Definitely a chicken/egg scenario. I woke up last weekend and heard a faint buzzing noise coming from the utility room. Opened the door and noticed it was actually from the garage. Opened the door and the dome light was on and pulsing in brightness with the "Fasten Seatbelt" sign, and the seatbelt buzzer was buzzing and pulsing with the dome light. Had apparently been going on for some time because the battery was low. Unplugging the dome light stopped the buzzing, but the buzzer sounds the entire time the key is engaged now and doesn't sound healthy. The door switches are all functioning normally and the wiring all checks out, no shorts or weird business going on, so who knows what happened there. The original dome light is definitely screwed though.

New dome light installed and a new seatbelt relay on the way (seems to be the slowest package I've ever gotten from USPS - assuming it ever gets here). The new dome light seems to work normally. As a nice sidenote, the light is significantly brighter than the original one too, despite having the same bulb, so I think something was up with that original unit anyway (it is transistor controlled after all).

I also got brave and installed the Monark injector nozzles I bought last year and never installed. Nearly 18 months old and never been out of that box. Shameful. Balanced all the injectors to 1950 PSI +/-25 and threw in the car. Good ol' nailing injector came back, this time on #6 (#4 was my previous problem child). Pulled and tested the injector and it wasn't the problem, so did another delivery valve swap. Took care of it once again! There seems to be a common trend here... The new injectors made a remarkable difference in how the car runs and drives. It seems to have a LOT more power, much more willing to accelerate, even at low RPM's, and the smoke under acceleration is greatly reduced. The engine is also significantly quieter, not that it was loud before. Should have installed those things a long time ago!

I've also been driving the Diseasel more than the Honda lately just because the A/C is so powerful. Jump in it after sitting in the sun all day and by the time you're to the end of the street the cabin temp is already noticeably dropped. Had it on the highway earlier this evening with an outside temp of 88 with the fan on high and was blowing 40˚ out of the vents. Can't beat R-12 on a hot day. I'm thinking about renting it out as a part-time refrigerator...

vwnate1 · #51 04-28-2017, 12:52 AM

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 .

Diseasel300 · #52 04-28-2017, 10:41 AM

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.

vwnate1 · #53 04-28-2017, 10:50 AM

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 .

Diseasel300 · #54 04-28-2017, 01:16 PM

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!

vwnate1 · #55 04-28-2017, 10:50 PM

! 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 ?

.

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

.

Diseasel300 · #56 05-12-2017, 03:40 PM

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!

jake12tech · #57 05-13-2017, 07:19 PM

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!

Bimmer-Bob · #58 05-13-2017, 09:13 PM

Quote:

Originally Posted by Diseasel300

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!

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

Diseasel300 · #59 05-14-2017, 01:06 AM

Quote:

Originally Posted by jake12tech

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!

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!

Diseasel300 · #60 05-14-2017, 01:15 AM

Quote:

Originally Posted by Bimmer-Bob

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'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!