if your going to have a shop look at it, he should have a smoke machine. otherwise, find another shop.

btw, that accum. was the absolute last thing looked at on that car. no vacuum leaks, perfect ignition scope and fuel pressure tests. it was a what the hell, what's left moment. good luck, chuck.

OK I appreciate that. I just put it on the car. I checked the Idle control valve by disconnecting it and reconnecting it Have not done the voltage check, It does what it is supposed to do, I guess I could take it apart and clean it as has been the suggested on some posts. Thanks

HI All

Tested the Idle control Valve, 4.65 volts, Gave it another smoke test. No smoke that I could see.

If I feather the gas pedal several times quickly it will shudder and if I do it about 6 times it will die.
Still about 900 rpm at idle. vacuum all the way to left at idle. Still looking for where to connect my real vacuum gauge. Thanks, J

Jack M, when was the Oxygen sensor replaced last? I have experienced a delay in acceleration in our 1991 300CE that a new Oxygen sensor resolved. As you likely have read in any Searches there are many possible causes for an acceleration delay. Better to diagnose the true cause rather than throwing parts at the problem.

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Fred Hoelzle

HI Fred. So the O2 sensor light on the instrument cluster is not on. Does that mean anything? J

Jack M, there was no warning light on the instrument panel with our 1991 300CE either. In an attempt to resolve the delay in acceleration I simply replaced the Oxygen sensor, and the problem was solved. If your Oxygen sensor has not been replaced in 100,000 miles it makes sense to install a replacement sensor … preventative maintenance.

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Fred Hoelzle

HI Fred. There is an O2 light on the instrmuent cluster. only comes on when you start the car, So it is is bad then would the light not stay on?