04-20-2012, 10:01 PM
My first post and I already need some help. I just put a 4.8 and 4L60E into my Jeep YJ. The motor is out of a 2001 Silverado with 89K miles. Computer is stock except to have egr, rear O2's, vats, etc. removed. Fired it up for the first time and after a few minutes the idle speed starts to flucuate a few hundred rpm. If I hold the rpm at about 2000 and then let off the gas it tries to stall. When I drive it, it seems fine except for when I come to a stop, the rpm drops and it sometimes stalls. Checked for vacuum leaks and I think there are none. No check engine light but I have not checked for codes with a scanner. Not sure where to go from here. Any help would be appreciated.