Stumble at take off when cold

I've had a bad set of 02's cause this, until the car got nice and warm it would not run correctly. (It also thru a code to show this so if you can check for it do so.)

Absent codes, I'd want to check the ECT voltage when it's cold (acts up).

Good luck.

spacemonkey,

That’s two votes for a bad Engine Coolant Temperature (ECT) sensor. But there’s another possibility as well.

I had the same problem, a stumble just barely off idle when I just got the first bit of pressure on the gas pedal. If I stomped the gas pedal down faster, the stumble was less noticeable. The more gradually I started off the more noticeable the stumble was.

For a while it only happened when the engine was cold, but then eventually it started happening at other times as well.

HISSIN50 figured my problem out. (I still owe him a beer!) I turned out to be a bad Throttle Position Sensor (TPS). There was a bad spot on it just off idle, which I was able to verify by back-probing the wires to it and reading the voltage with an old analog VOM as I opened the throttle by hand.

I replaced the TPS and my off idle stumble was gone.