Ok did the test on the TPS. Got a consistant sweep of 0-3.4 volts. I coudlnt get the MAP sensor to sweep. Voltage was all over the place. I dont think i was getting enough vacume to it. But i dont think its the MAP sensor. It doenst surge at highway speed.

 

A f***ed up MAP can cause all kinds of wierd problems, and they really don't like to throw codes. I recently had a Buick 3.8l Series II that would intermittently stutter, surge, stall, buck, etc., etc. The intake manifold gasket had failed, and dex cool vapors were eating away at the MAP. Never threw a MAP code.

Without a good signal from the MAP, the PCM has no idea what the engine load is. Absolutely critical component; moreso than TPS and O2's.

 

which sensor is most affected by engine temp. It tends to stall more if the engines warm.

 

ECT, but that's used for start-up. Once in closed loop, the PCM does not use the ECT to calculate fuel trim.

Are you sure you're not loosing spark or fuel?

You're probably gonna end up spending less if you just take it to a good shop and pay the hour diag for someone with a scanner and scope and a few years experience to track down the problem.

 

Yeah thats what im thinking.. It might be fuel. I was running out the other day and the syntoms got real bad.

 

Well it was the TPS. I cleand it out yesterday and its run great since. Seems like better throttle responce now too. So id say you can have symptoms that seem like a IAC that could be coming from the TPS. Manuel says both sensors control idle.

 

good to hear you got it running again.