What can cause a 944 N/A to go into open loop after the engine warms up?
I can't get off idle without it choking.

 

bump

 

Vacumn lines.

 

Thanks for the idea. We have checked all potential leak areas and it's still no better. Trying to get in touch with Jim Vitesse but no luck.

 

TPS maybe?

//Magnus

 

How did you come to the conclusion that it's in open-loop mode?
Disconnecting the O2 sensor will alter the engine running, but not to the extent that it "chokes". You need to check the igntion system, fuel pressure and for intake leaks first. What is the CO reading (taken before the cat with the O2 sensor disconnected) at idle.
I would agree that the problem maybe the TPS or if the fuel pressure is excessive, the fuel regulator.
More information and diagnosis required.

 

I was trying to tap into the O2 sensor to give a readout of the problem. Turns out the wire to the DME is shielded and to get to the real one you have to go almost to the pin at the DME. Once this was done, I got what I was looking for. What I found was instead of open loop (if I understand it correctly), it was going so lean as to not run. My experience, until this car has always been with the old muscle cars and my 944 sounded for the world like a stuck choke on the old cars. No to be. What it needed was more fuel-alot more fuel. Another thing that was confusing was the cold start mode this car has. Once the correct wires were tapped into to give the smt6 the info it needed, now I have the cold start/warm engine change over cured. All that's left now (I hope and fingers crossed) is to tune the engine under road conditions. If all goes well, and it's anything like the little driving I did before the problem cropped up, the butt dyno will agree that there is a definite increase in HP. Thanks for responding.