Help! Runaway idle speed

[Moriartyhlms]

Hello, I'm having some issues with my newly rebuilt engine and am hoping for some forum wisdom. Occasionally, my engine's idle speed will start running away and I have to get off the road and shut down before it gets too out of hand. This only seems to happens when the car is warmer (LA traffic), and always returns to normal once I restart the engine. I'm thinking it may be an Idle Control Valve or Fuel Pressure Regulator problem. Thoughts?

My car is a 90' 964 with 993 vram/injection/DME/Wong chip.

[Moriartyhlms]

Second problem is that the engine seems to choke up if I move the accelerator too quickly. As in; when 'floored' the engine will make stuttering noises and not give any additional power, but if I roll accelerator on slowly the engine seems to keep up just fine.

Thanks
-Sam

[afterburn 549]

not a whole lot to go on, My guess "false air"

[txhokie4life]

Air is entering intake past the what ever air monitoring system you have.

Maybe a leak at the intake runners where as the car heats up gap opens.

I had something similar on my race car.

Mike

[Moriartyhlms]

Did some more experimentation today regarding issue 2 (choking under WOT at higher revs and load conditions); I think it may be a bad resonance flap or something else internal in the varioram. Any ideas?

And thanks for the above replies, I agree that 'extra air' finding it's way in could be an issue, but I still thinking it seems like something's getting stuck then resetting once I restart. So Idle Control Valve or throttle linkage/bell crank.

Thanks again.
-Sam

[Moriartyhlms]

And Mr. Afterburn 549, we should talk helicopters.