Ok, maybe this is a stupid idea, since there is really nothing wrong with my ip that I know of. My car, 83 300DT, 305,000 mi, smokes on start up, a problem I am going to work on this weekend, but I don't have any reason to suspect the ip. However, I was at the local junkyard today and there was a wrecked (side collision) 82 300DT, 165,000 mi, with a bright shinny ip. The thing looked new and and the lines to the fuel injectors were shinny, too. Maybe the injectors are new, too. I'm assuming I could pick it up for a song. Any advantage to replacing mine when it doesn't appear to be broke? Am I just asking for trouble? Should I buy the new one just in case? Should I buy it and re-sell it here?

Just thinking out loud.

Murphy says to buy it and keep it on ice.

Sixto
95 S420
87 300SDL

pick it up for a song and give it to me. I'll keep it on ice....

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Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Describe your smoke more: When does it do it? What color is it? Has it always done it? All old diesels smoke a little on start up, now that it is getting colder they smoke more.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I hadn't wanted to start a smoke thread, but since you asked...

She smokes heavy white smoke on startup. Or actually after startup. She'll start without smoke but run rough and then start smoking while I let her warm up a little to smooth out the idle. She just started this a couple of weeks ago, started with a little smoke and now smokes more heavily. It hasn't gotten cold down here yet.

I had a problem with the car stalling on decelleration. I replaced some fuel lines, replaced both fuel filters and did the diesel purge in a jar thing only using sea foam instead of diesel purge. The stalling stopped but the smoking started or at least got worse. Problems I will fix tomorrow are a broken air filter housing bracket and a loose fitting rubber vacuum connector on top of the valve cover.

She still runs fine when warmed up. I timed 0 - 60 in 15 seconds.

Last weekend I took the EGR valve off and cleaned it. It seemed to be working allright and opened when I applied vacuum. I gave it a good cleaning anyway but it had no effect on the smoke. A couple of weeks ago I replaced the vacuum lines leading to and from the temperature activated vacuum switch at the EGR valve. That was about the time the smoke started. Replacing the rubber connector on the valve cover may help the EGR. If not I may tinker with it, disconnect it and see what happens.

I also checked the glow plugs with a meter. All had around 1 amp resistance. I think I'll take them out and see if they glow. Then clean them up. I've never fooled with glow plugs. Spark plugs get pretty fouled up over time, I supposed glow plugs can too.

If that doesn't help I think I'll check the valve clearance and see if I can figure out how to check the timing chain for stretch. Then the ip start of deliver. I'll need a tool for that. Then I'll check compression. Another tool needed. Then I'll pull the injectors and have them tested.

I pulled the fuel sending unit because I had missread a post and thought I could clean the in tank screen that way. I couldn't, but the metal on the fs unit was coated with a black oilly residue. The fuel in the clear in line fuel filter is clear with a slight green tint. I wonder where this residue came from and if the screen might be clogged by this. Any way to tell without pulling the tank? Maybe I should have the tank cleaned.

Does the above sound like a good plan? Do I need to check anything else for the problem? Most of these were suggested by the many smoke threads I found on this forum. I may have missed some or forgotten others. This car did have a smoking problem when I got it last year and it seemed to go away when I replaced the air filter housing which had a bad oil separator and let oil flood the filter housing.

One more thing I did was clean out the vacuum line from the manifold to the vacuum switch on the firewall and the one from the vac sw to the ALDA. I gave the ALDA a shot of the brake cleaner through the hole the vacuum line attaches to. I decided later that I probably shouldn't have done that since there's probably no outlet for the fluid. It should have dried up by now. I hope that didn't damage anything.

Thanks,
Mark

Mine skips once in awhile on start up also, I would get your injectors checked by a good diesel shop first. That way at least you know their up to spec, a leaky injector willm cause a skip on start up and a lot of smoke.

Btw you are supposed to break the egr not help it! Those things are horrible for a diesel!

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

LOL. It shouldn't be hard to break. That vacuum system has a lot of possible failure points.

Today I checked the glow plugs and they were all getting around 9.5 volts and were glowing red hot. I pulled each plug and wired it to it's wire and to ground. Then I cycled it with the key switch. They all glowed red until the relay kicked off. One seemed weaker than the others and I may replace it.

I had taken the linkage off to reach the plugs so I went ahead and pulled the camshaft cover. I only had time to check and adjust one valve, but it was too tight. Makes me think that the valves are the problem. Maybe it wont rain tomorrow and I can finish this.