Smoking, carboning, poor cold off idle with little to no blowby. What could it be? - Page 2 - PeachParts Mercedes-Benz Forum

lietuviai · #16 02-29-2004, 04:23 PM

Quote:

Originally posted by Eric Eliel
Just is really simple and sounds a little like the problem I had recently. Have you checked all the vacuum hoses that go to the IP and the ARV and the EGR? Make sure the EGR is plugged but also the hose isn't leaking, same with the ARV next to it. Also check to make sure all the various hoses going to the IP are installed and fit well. I think somewhere along the line, one of my hoses was loose causing some of the issues you describe.

Sure you are getting clean fuel and the filters are plugged?

Worse case I have a guy here in SO CA that can test and rebuild your IP for much less than the "on-line" places. He has the Bosch IP test bench. You can PM me.

I've done just about everything short of replacing the IP and injectors on the car. EGR? I've taken care of that. What is the ARV? Would a CA model '85 have that?

#17 02-29-2004, 05:13 PM

ARV = Air Recirculation Valve

I think it acts similar to a diverter valve, or a blowoff valve on a turbo gasser. It supposedly reduces turbo lag once you're at speed.

BoostnBenz · #18 03-02-2004, 03:18 PM

I don't appear to have any vacuum leaks at all. As far as I know there isn't any ARV on my car. I believe my problem is the opposite though, either it is getting way to much fuel or more likely it just isn't burning it properly due to something in bad timing relative to something else.

Did your car smoke all the time or idle differently before installing the woodruff keys?

No I haven't pop tested the injectors unfortunately, I call around but nobody really has the setup for it. I'll have to buy a new fuel line and ruin that to test them as they are metric versus the other bosch injectors having standard threads. I don't believe that the springs get weak however the wear in the nozzles may allow the pop pressure to go below the 1750psi service limit. I would bet a poor spray pattern or leaky set of injectors could create these same symptoms of smoking most of the time, however at one point in time two of the injectors were swapped out leaving the other three factory. Now this in itself may not mean a lot but when I pulled the GPs all five are equally carboned with a lighter dusting of it about the whole length it is inside the motor.

When installing my prefilter I made a point of eliminating 95% of the air in the prefilter so that if I ever had a problem with leaky lines that it would be quite noticeable when looking at that filter.

My compression gauge and that whole setup is giving me problems hopefully I'll get those values through the week. What is the service limit for that again? 250ish?

psfred · #19 03-02-2004, 03:24 PM

Quiet running is a sign of late injection timing. So is smoke.

Double check the injection timing, and get the injectors checked -- any diesel injection service can do this, check the yellow pages. Even if you are in outer mongolia, someone around works on diesel engines.

And plate off the EGR -- if the valve is stuck open (or sticks when opened), it will produce EXACTLY the symptoms you have. A broken closing spring on the EGR will allow it to stay open all the time, and you will get HUGE amounts of smoke at low speeds, along with snail-like performance.

If that's not the problem, it's time for a compression check, and likely a valve job.

Peter

BoostnBenz · #20 03-02-2004, 05:40 PM

Yes the timing was way late before, so I suppose if the same guy who did the timing did the injectors then perhaps it is time for new injectors to!

I talked with a guy who owns a tractor shop right around the corner and he said he has a new tester but no adapters for the 300D's bosch injectors, he has tried it on other vehicles but the bosch for our cars are a different fitting than that of other bosch injectors. I guess I'll call around a few other shops see if they have anything good to say.

It is set to 14* ATDC (IP lock tool) correct?

I can't find the EGR valve, I think it is missing!

I'll mess with my compression gauge again today to see if I can get it to cooperate, it is hard to get the fittings in such a small area like that. Anyone know the service limit? It seems like the new motor has around 400-450psi or something like that, most are in the 300s and service is below 250psi!?

lietuviai · #21 03-02-2004, 10:13 PM

I got my smoker running half-way decent today. I poured a quart of auto tranny fluid in the tank since it looks like the famous Marvel Mystery oil. I've heard that MM oil can sometimes help ailing diesels. I got on the rear bumper and bounced the car up and down to get the oil mixed with the fuel. So I got the car started, held my foot on the pedal to keep it from stalling, put it in drive and went for a ride. It ran terrible, it smoked and was sluggish until it was warmed up. So I then got it on the freeway and floored it. It stumbled and missed at first and then belched out a huge cloud of smoke. So I proceeded to give it an Italian tune up and ran it as fast as it would go in third gear for several miles. The smoke cleared up and it seemed to run OK. I then ran it back home, this time normally. At idle it still has a bit of a miss and the idle seems to go up and down slightly rhythmically, my guess about 100+/- (tach non-op) and with an occasional miss. But at least it now idles again on its own. Still have a sound of what I think is a couple of noisy injectors. I'll have to see how it runs tomorrow morning.

shane83SD · #22 03-02-2004, 10:40 PM

Found some related info regarding smoking diesel on another list:

http://db.mercedes.cx/mb/200002/03/0082.html
http://db.mercedes.cx/mb/200002/05/0014.html

and injection timing:

http://db.mercedes.cx/mb/199407/0411.html

BoostnBenz · #23 03-02-2004, 11:49 PM

Perhaps I can come up with a hypothesis that by driving the car softly with the valvetrain 4* late and the fuel delivery 1* early I'm causing the motor to carbon up easily. The more it carbons up the worse it runs and more it smokes. Quite often after running it hard there is little to no smoke once I begin idling again but a short while later especially if I set at a traffic light to long it'll begin smoking again.

Thanks for all the replies so far, I guess what I'll do is pull the injectors and try to get them tested, run a compression test, then order/install the woodruff keys along with adjusting the valves to the new setting.

I believe the ATF would have just raised the cetane level temporarily which also helped clean the motor out. It sounds like you may need some new nozzles for your injectors.

lietuviai · #24 03-04-2004, 03:07 PM

Quote:

Originally posted by BoostnBenz

I believe the ATF would have just raised the cetane level temporarily which also helped clean the motor out. It sounds like you may need some new nozzles for your injectors.

I will be finding out if my nozzles need replacing fairly soon. I've got a set of known good injectors coming and that should tell me for sure.

BoostnBenz · #25 03-04-2004, 05:04 PM

Well I hope it does the trick for you. Not much new with my car, haven't had a lot of excess time lately. My talon has been getting me almost 25mpg so no real complaints there, it just rides rough.

lietuviai · #26 03-11-2004, 07:49 PM

I think that I got fed-up with diesels today. I put in a set of rebuilt injectors from a reputable rebuilder for my car today and its running worse than it ever had. I did everything like I was supposed to. I tried to make some adjustments but it didn't help. I'm sick from that awful diesel smoke. The garage stinks, the car stinks, and I stink from diesel smoke. I'm think I'm just going to put the old ones back in and and throw in the towel.

BoostnBenz · #27 03-11-2004, 11:06 PM

My parts came in today, I got a new adjustable voltage regulator, some new seals, 2* woodruff keys, and a few other little things so it should soon be back on the roads. I'll probably be spending most of the day tomorrow working on it, whether it smokes or not it'll be back on the roads next week. I was under the impression my compression tester was sent from NJ but I now realize it was sent from hell, nothing but problems with the friggin thing. I now have the right fittings, the gauge calibrated, but need to get the one way valve on it working properly so I have a stab in the dark sort of figure for my compression.

Sorry to hear of your misfortunate problems with your 300D lietuviai. Are you sure your timing is right?

lietuviai · #28 03-12-2004, 01:09 AM

Quote:

Originally posted by BoostnBenz
Sorry to hear of your misfortunate problems with your 300D lietuviai. Are you sure your timing is right?

Never touched the timing. I don't think it had anything to do with the timing. My guess there is something bad with the injectors or the pump has finally gone bad. The old injectors are going back in as soon as I find time.

BoostnBenz · #29 03-12-2004, 09:44 AM

So far doing the timing has single handedly made the largest difference in my reduction of smoke and low end performance! I presume you've already checked your chain elongation and it is a reasonable number, less than 6*. The lock tool is made by SIR for mercedes, I believe it is item number 1060 here, they seem to have the best price on it of only $36 shipped. That is unless you want to wait for a drop shipment order which wouldn't be much cheaper but take a couple weeks rather than a couple days.

Is it possible that the new injectors are better but since the timing is so far off that the vehicle runs worse?! A quick but not very accurate test to see how close your IP is timed with the motor would be without the above tool if you pull the plug out of the IP (remember to catch the engine oil) and rotate the motor to 15*ATDC, if the car is timed correctly you should be able to see the peak of the lobe with a mirror. This peak is where the lock tool sets on, it is kind of hard to see though so it may be a better use of time to just wait until you have the lock tool.

Even if it is the IP that to me really isn't a big deal, there are a LOT of them to be had out there cheaply ($50!). It is just the tedious work of installing one, primarily having to pull the filter housing so the IP can be pulled out and new one reinstalled.

240Joe · #30 03-12-2004, 10:23 AM

In my 83 300D, it is possible to remove the IP without removing the oil filter canister. I did it twice.

That being said, I'm not saying you should remove the IP because I can't figure out what your problem is and what you tried to do.

Bad maintenance on these cars is worse than no maintenance. My 300D was smoking terribly when I first got her because the previous owner had someone try to tune it up by adjusting the IP timing....big mistake.

240Joe