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I have a 1981 380SL that has a rough idle and poor acceleration for about 5 minutes just after starting when engine is cold. The car runs great after that, although infrequently it will cut out when coasting to a stop. Any ideas?
 

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Thanks

I'll look into these. I've got a CD version of the manual, which is quasi helpful. Someone told me that it could be a bad temp sensor, but there are 3 of these mounted in the front of the engine. Do you agree that these are worth examining, and if so, which one sends a signal for fuel injection?
 

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I have a 1981 380SL that has a rough idle and poor acceleration for about 5 minutes just after starting when engine is cold. The car runs great after that, although infrequently it will cut out when coasting to a stop. Any ideas?
If you would put that 1981 380SL in your profile, under the user control panel, it simplifies things for everyone. Specially us over 50's.
The accumulator can often give fuel starving symptoms as described. Used to cost a hundred, haven't priced them lately. Don't go expensive if you don't have to. Ron, at GermanStar, will do you right.
That ought to be worth some mod points, to be brokered later.
 

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Thanks to IsthisDave and Benztoy. It's good to know your out there. I'll try some of the tests listed in the link.
How do I enter a profile? I'll also give a shot at a picture (Avatar?)
 

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1980 450 SL
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My '80 450SL had identical symptoms (other than the random cutoffs), and it was cured with a rebuilt warm-up regulator from GermanStar.

I don't know whether the random cutoffs point to a different source for both problems, or whether it's coincidental. My guess is that it's coincidental.
 

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I have the same problems, checked and replace the plugs and wires, fuel pump. ohm the warm up regulator 18ohm where it is supposed to be. I suspect either a bad fuel pressure regulator, accumulator or bad cold start valve. I read that the warming element in the warm up regulator can be good but the diaphragm bad and need cleaning. problem with that... it needs to be adjusted after opening and its a pain.
 

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Forum Administrator , RC Colas® & Moon Pies®
1981 380SL 151K: 2005 S500 116K
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Thanks to IsthisDave and Benztoy. It's good to know your out there.
Some of us, on the other hand, lock our doors and windows tightly at night for that very reason.


Meanwhile...

Let us know how it turns out McG. Good hunting.
 

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1998 SL500, 1959 220S, 1970 280SL
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If the car(s) start easily, then don't worry about the CSV or TTS, since they are only active for a second or two, and then only below 50 degrees. The warm-up regulator is a likely culprit, but it's an expensive gamble. You can buy a pressure gauge setup for about $40 and test it.

One common problem with WUR's that has an easy fix is that the inlet screen gets clogged and raises control pressure. You can unhook the large line, unscrew the fitting and fish the inlet screen out with a pick. It has four layers of mesh. Clean it with carb or throttle body spray and reinstall.
 
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