Manager Forum

Idle surges bad when cold, up and down, like a vacuum leak. Had a bad IAC vlave and a vacuum hose, but the problem is still there. When it warms up, you can barely tell there's a problem. It has to be really cold, like first thing in the morning. Just wanted to let you all know IT'S FIXED! It was the lower intake manifold gasket. Thanks for all the input. Hope this helps someone else.

Watch your maf. If it's low, rev it up for a little while and then let it idle again. If it goes back to normal and then starts getting low again, you have another leak somewhere.

Yea, I agree. Aren't they ones with those plastic intake manifolds and little rubber o-rings in a grove for sealing? I have seen numerous problems with that design and replaced them for the same symptom you are describing. You could even have a warped or cracked intake manifold.

What are the fuel trims when this happens

what is the scanner reading as a temp reading. if it's reading high from a shorted sensor that will cause the issue.