Wierd idle issues

[georryan]

Ok, so since this part of my talk about getting my car done is more pertanent in this forum I'm going to post it.

I thought maybe the idle issue I was having was due to the computer learning around the lightweight flywheel, but that doesn't seem to be the case really.

What happens is when the car is first started, it will idle fine for about a minute, then it drops the idle down really really low, to the point where I think it might die. It will pick up again a bit, but when I take off to drive, it will act like it is being starved for fuel and stumble. It will catch every once in a while and be fine only to stumble again. Once the car is warmed up, the problem disappears completely. It drives completely normal.

I've changed and gapped the plugs. Everything worked fine in my last engine. So I was suspecting new parts, or new combination of parts to be the culprit, now I'm not so sure.

Would a fuel pressure regulator do this? Coolant Tempurature sensor?? IAC valve?

-Ryan

[georryan]

Oh, and no codes are being thrown.

[Threshld1]

what plugs did you put in, i assume NGK. i had the exact same problem and i was using bosch plats and i swaped them for NGK and runs like a dream.

What kind of vac are you seeing at idle?

[georryan]

Vaccuum is good. It's at 16 or 19, I can't remember.

The plugs were the right plugs: NGK BRK6E11. I don't think it is a vacuum leak. If it was I'd see it all the time, not just when it is cold. My boost guage shows vacuum as well, and it hasn't been acting funny in any way. I'm starting to question the coolant tempurature sensor, but I'm also not looking forward to changing it.

[georryan]

So I've noticed that if I shut the car off, then start it again, the issue comes back, even if it is warmed up, but if it is warmed up, it quickly goes away.

[georryan]

Ok so an update. I noticed the other day that it doesn't do it anymore. There are a couple factors: I changed to my stock exhaust to smog my car, and I put in a fresh tank of gas.

So one, it could be exhaust related, which I think is highly doubtful. Two, it could be the ecu relearning things (also highly doubtful since other people have had similar setups without problem. Three, the full tank of gas that was sitting in my car was causing an issue. This might be it, but I really don't know.

I'm not sure what was causing it since I can't diagnose a non-existant problem anymore. I guess I'll just see if it comes back after switching back to the CES exhaust.