Cold start up & hesitation Issues
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 862
Likes: 41
From: Mahwah NJ
Cold start up & hesitation Issues
I have a 91 L98 that I just had rebuilt to a 383 stroker with a lingenfelter super ram, 222-230 crane cam and ported pro line heads, 26# injectors. I've been through 21 computer chips from Formatos Fast Chips (Lingenfelters chip maker) and still have 2 Issues.
1) On cold start up only, It searches for an Idle for about 45 to 60 seconds and then idles fine. It varies from 600 rpm to around 1300 rpm.
2) Under normal city driving I experience a slight hesitation between 2400 rpm and 3000 rpm and then the car excelerates at 3000 rpm as if I just hit the gas pedal harder.
I have no Issues at all when under wide open throttle at the track.
Any Idea what might be going on here? The chip maker Is stumped
1) On cold start up only, It searches for an Idle for about 45 to 60 seconds and then idles fine. It varies from 600 rpm to around 1300 rpm.
2) Under normal city driving I experience a slight hesitation between 2400 rpm and 3000 rpm and then the car excelerates at 3000 rpm as if I just hit the gas pedal harder.
I have no Issues at all when under wide open throttle at the track.
Any Idea what might be going on here? The chip maker Is stumped
Safety Car
Joined: May 2003
Posts: 3,789
Likes: 0
From: [Quote=WOEII] Is dried brown doodie powders man! [/Quote]
I had just woken up when I replied and re-read your post and see you have an SR. These things are notorious for vacuum leaks. I would get a vacuum gauge on there to see what it was pulling in reference to what the cam mfg says it should be pulling.
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
Did you set the IAC to about 10-20 counts? Is the TB and the IAC housing clean?
They did that setup for me and it worked flawlessly. Are you positive there are no leaks on the SR setup? Check the runners and the lid again with a can of brake cleaner
They did that setup for me and it worked flawlessly. Are you positive there are no leaks on the SR setup? Check the runners and the lid again with a can of brake cleaner
Safety Car
Joined: May 2003
Posts: 3,789
Likes: 0
From: [Quote=WOEII] Is dried brown doodie powders man! [/Quote]
Basically it's how many counts, or steps, the ECM is moving the pintle to maintain idle. IAC counts can also point to a vacuum leak as the ECM is trying to compensate for the higher idle caused by said leak.
