Misfires when it warms up... why?

[hawkeye217]

I dont see how it would be the timing if its fine in the cold. Sounds like they are stalling cause they cant figure it out lol.

Hahaha those were exactly my thoughts!

I've checked the timing myself 3 separate times... But I said "hey, if that's what you guys wanna do, go for it".

I'll let you know what they come back with today...

[kildaremike]

I dont see how it would be the timing if its fine in the cold. Sounds like they are stalling cause they cant figure it out lol.

I dont know if you guys have automatic chokes but if it is ok from cold and goes funny when it warms up it could be a fuel problem that the choke is covering up from cold.

[hawkeye217]

The guy at the stealership said that the crank sensor plate (is that thing also called the reluctor wheel?) is bent, which may be causing the issue... More to come after I hear back!

[hawkeye217]

Well, it partially fixed the problem.

The barometric pressure sensor is reading low, like I'm in the Himalayas or something - so it's causing the car to run lean when it warms up!

The supply voltage from the PCM is bad - it's supposed to be providing 5 volts, but it's only sending about 3.2, which is causing the sensor to read low.

The immobilizer and PCM have to be replaced together for the thing to not throw an immobilizer code and not start (the dealer and I tried a salvaged PCM from a 4G64) so we know first hand that just reprogramming the keys won't work.

So I'm going to try to hack it - I need to find a PCM pin that is sending 5V and then splice it out.

[milo111000]

wow goodluck bud keep us updated

[hawkeye217]

Well, I hacked it, applied the 5v from a small circuit I made with a 7805 IC connected to the cigarette lighter... Radio shack homemade special for only about $10. The baro sensor then gave me a value again, but I have a feeling it was still low.

It was fun to hack it, but it looks like the ECU is the culprit, and I don't have any more time, money, or motivation to dump into it. I got it back on the road, drove it about a mile, and then it started running super lean again until it stalled. Sitting idle in the dealer's garage, the short fuel trim was normal. Too bad I couldn't take it out for another run with the dealer's computer monitoring everything...

I think I'm going to craigslist it - blue book is still $3000, but if anyone from the forum wants to buy it for an amazing deal, PM me! :)