engine idle

[troomi]

hello folks,

i have been noticing an engine idle fluctuation over the past several months. i have an unmodified engine/exhaust & a stock air filter (2000 box s).

the problem is when i am at stoplights. the revs drop down to where a slight shuddering is felt (like its going to stall), then they go back up. this continues for the duration of the stop.

i have had the maf changed/reprogrammed, but to no avail.

do any of you folks have any insight into this?

regards.

[mrmickeymouse]

Diagnostic: Infrequently, the car will spontaneously drop the engine RPM to almost zero, then seem to catch itself and resume back at the original RPM.

Cause: Unknown.

Details: A number of owners of Boxsters have this problem while the car is idling. Some people have a direct correlation with the air conditioner being on, whereas other people have had the problem with the air conditioner off. Only some Boxsters have this problem. Some people think it might be a bug in the Boxster's computer controlled electronics. Unfortunately, it is not reproducible on demand, so debugging it is difficult. There is currently no fix, and PAG and PCNA have not even admitted the problem exists.

It seems there would be a software patch that could cure some of your problems.

[Tool Pants]

There is an idle control valve but I have never played with it.

When Chris worked at Stevens Creek Porsche I asked him what to do with a hunting idle problem, which is not exactly what you have. He suggested cleaning out carbon from the throttle body with a spray can of carb cleaner. Worth a shot since it only cost you the cost of the carb cleaner to see if that helps.

[troomi]

gentlemen,

thank you for your response. i will attempt the dealer/pcna route once more. failing that, i will attempt what jeff suggested.

regards.