hot starting - revisited

[adrian jaye]

A while ago I had an occasional hot start problem. in that car would turn over, and then stall.

thats is long drive, stop for a few mins, wont start
take a long drive, stop for more than say 20 mins, no probs.
cold starts no problem

again very intermittant.

I replaced DME anyway (but was only done a year ago so cant see it being that)

was suggested that the ICV might be sticking, so as advised, removed airfilter and when engine hot, squirted carb cleaner into the intake, then afetr doing this for a while, I then sprayed WD40 to lubricate.

not been able to re-test the failure,

but can anyone see anything thats been missed ?

may possibly look at changing or cleaning the ICV properly

oh the other thing I noticed that a lot of the relays were REALLY
hot, including the DME and ignition relays, the under bonnet temp was quite high, does anyone know if this is a problem ?

also I read that when the fuel pump is on its way out it will try to
draw more current, possibly the DME relay may be failing prematurly cuase of this ?

cheers

A

[Tx951Dude]

I think that I have a very similar problem. My 87 951 starts fine when cold but takes forever to start after sitting for less than an hour. It has new plugs, fuel filter, O2 sensor, new $1200 Porsche dealer cat. for passing Texas emissions, etc. The only thing that gets it started is by pressing the gas pedal to the floor, holding it down, releasing, pressing down to half throttle position and then starting again. It usually takes about 5-10 minutes of this before it finally starts. It's frustrating because running short errands is almost impossible unless I have time to waste between stops waiting for my car to start, not to mention very embarrassing when you're driving a Porsche that won't start up when you attempt to leave a shop! Arggggggggggggggg!!!!

[Moneyguy1]

Test your fuel pressure.

A leaky injector or a bad check valve will do what you describe.