rough idle, loss of power.

[peytonracer4]

i have a rough idle on cold starts. it will idle very rough and die after a few seconds if i don't give it gas. when i unplug the maf it idles high but steady.

also when i accelerate under wide open throttle the engine feels like it's being held back. like it's hesitating almost, then after 4k rpms it pulls good.
i have the exhaust off other than the headers. could this be causing it? i thought maybe a dirty maf or a vacuum leak but the car idles good when it's warm. it has the laggy acceleration no matter what though

the car is a 318is

thanks

[jlevie]

My first suspicion would be intake leaks. Have a smoke test run.

[Rook12V]

I agree with Jim, it certainly sounds like a vacuum leak, and they typically are worse when cold. Alternatively your maf could be bad, but its probably not.

If you can't easily have a smoke test done, you can spray around the air induction system with carb cleaner and if the car starts revving, then you just supplied a little fuel to the motor, through your air leak.