i have recently put a 94 lt1 in an 88 chevy 4wd pickup. everything seems to be great except for the transmission and high idle. it seemed to be shifting fine at first after adjusting the detent cable but i still had the high idling problem so i parked it, so i could fix the high idle. the idle is fine when i first start it but after a min. or 2 it reaches up to about 850 rpms. i had the harness and comp. sent off to work in this truck and the comp. was programmed to 650@idle but there is something wrong there. does anyone know. as for the transmission now it does not want to shift at all. like i said at first it was fine the torque converter lock up kit seemed to be working fine but after sitting for a few days b/c i was working on the idle it does not want to shift at all. it is a 700R auto. transmission behind it. is the transmission shot? could really use any help i could get. thanks

 

If it happened all at once, I would look at the governor gear being broke or stripped.