Low rpm problem after starting hot 964 turbo engine..
 

Guys,
unfortunately my car has a strange problem that happened 5 times already.
When I start a hot engine, it starts without a problem, but has very low revs and almost dies, the AFR is 20.00, and this only happens when the engine is hot.
If I press the gas and exceed 1000 rpm everything works normally, when I take my foot off the gas its about to go off.
This morning I started the engine normally and drove to a meeting for 30 minutes. After an hour I came back and what I described above happened. Despite the low rpm and the engine not running smoothly, I drove further. After 10 minutes of driving, everything returned to normal, the AFR at idle speed was again 15.5-16.0. I went to a meeting and after 10 minutes I came back, got into the car, started the engine and everything was fine.
Does anyone have an idea what could be the cause?

Thanks
K

Sounds like your Warm Up Regulator may be malfunctioning. Would need to hook up a set of CIS pressure gauges to verify.

I have a similar issue. There are some pretty old threads about this issue and it sounds like the consensus is that the WUR can get heat soaked on hot days/from a hot engine. While the engine is cool enough it needs the addition fuel, the WUR thinks the engine is warm because the bimetallic spring is still heat soaked and in WCP mode.

Can't find related threads can you help me please?

I think this is the thread I was thinking of - you may try another search with a variety of terms, e.g., "low idle hot start", etc. and see if you have more luck.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/633757-crap-idle-after-heat-soak.html

I would love some more insight into this as it is pretty annoying during summer time in Dallas.

Any new ideas guys?

Have you had your CO adjusted? Might be worth a look and it is easy to do.

Best of luck,

Rahl

One thing I’ve notified with mine - with the benefit of an AFR gauge - is that it’s definitely a bit lean when running like crap after heat being heat soaked, but also has a rough and relatively low idle. I’ve been checking my AAR and it’s staying closed for quite a while after shutting the car down. Coincidentally, if I start the heat soaked car and hold RPMs around 1500, AFRs are normal, etc.

So is the car initially running rough because it needs AAR open, and without it open, there’s a low/rough idle, in turn negatively affecting AFRs? Or is it an AFR problem causing rough running and the AAR isn’t needed for anything other than a true cold start?

In any event, I’m very close to installing hand throttle mechanism I’ve had on the shelf for a few months.

Soooo, you are not going to try and adjust your CO mixture?

Rahl