Would not hurt to add some injector cleaner for diesels to a full tank of fuel. The smoke and roughness could be uneven spraying injector nozzels. Any large truck stop will have it. If the temperature gauge is within the normal range upon restart, just turn the key like any other car and start it. No need to warm an already warm cylinder.

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

Thanks. Well as stated in another thread, I have a loping idle when the engine is warm, only when its in park. When in gear and idling, it goes away. The car has been setting awhile. It would be neat if that was the problem with both of these issues!

Crank it after the GP light goes off, you should almost never have to touch the pedal. The 603 has ELS that keeps the idle constant, I think yours does as well.

Electronic idle control is sweet!

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Yes, after the yellow FP light goes off, it starts almost instantly when cranking... but if you do not give it some acceleration after it starts, the idle stays low and it stumbles... maybe its normal for those car.

Nope thats not normal, should light right off like your Lexus. Especially this time of year.

First get a FSM, than dive into it.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

FSM? Shop manual? There is one with it, so I guess I will have to read up...

If not, sell it to my uncle that wants it badly. (Then buy a Toyota )

I cannot believe the MB tech that checked this car out 5 months ago did not do anything about this. He said it just needed to be driven. It had set another 5 months since he said that though.

Hopefully its just a clogged injector. Just does not make since why it is fine on the road though- while driving.

When I test drove this car, it was not doing it much at all. Seems like it got worse the past couple of times I have driven it. I was assuming all was normal at first, since this was my first diesel, but now I am learning different of course.

I think your worrying about it to much. When I cold start mine after sitting for a day or two it tends to stumble once or twice at random within the first 10 seconds. Im almost certain its air leaking into the fuel system. Dont worry about it. If it starts it starts.

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1981 300SD 512k OM603