Engine cuts out when hot

[georgethackray]

Hi. I have a hot running problem with my 1990 944 S2 Cabriolet. If the engine gets hot after say 20 minutes, then I stop the engine, it will start OK but it cannot maintain it's revs - once I take my foot off the gas the revs drop right down and the engine stalls. This happens for up to 3 hours afterwards depending on how hot the engine was. Even when driving if the revs drop to under 1000 it feels like it has no power and is about to stall.
If I drive the car for half a mile, everything returns to normal and the engine starts and runs perfectly. The engine also starts and runs perfectly from cold.
Any ideas what the fault might be?

 

[mikead]

George

205 GTI's frequently suffer with the same problem, with the usual suspects being the ICV failing to close or a faulty temperature sensor failing to 'tell' the ECU that the engine is hot. There are a couple of other areas that I would check also - airflow meter - vacuum & breather pipes etc. Have you checked to see if the spark plugs are a normal colour? This may give an indication as to where the fault lies.

I am pretty sure that someone more technical will be along soon to offer more specific or contradictory advice, but I'm sure the fault can be rectified quite easily.

Hope you can get it sorted quickly, apart from being a PITA it's also embarrasing to look like you've stalled at every set of traffic lights!

 

[georgethackray]

Hi Mike,
Thanks for that - I know the Air Flow Meter is fairly new (of course, this doesn't mean it hasn't failed), I'll have a look at the Vacuum and Breather pipes, and the spark plugs should be easy for me.

The idle control valve looks like a candidate - unfortunately! I just saw the price on Pelican Parts!

The car is covered by Hartech but I always like to try to find out what might be wrong before it goes in.