y5mgisi

iTrader: (2)

Swapped a 02 denali lq4 into a 91 suburban in place of the TBI 350 the original 4L80E was left in place. We did the swap using a 04 express van modified harness. We upgraded the trans internal wiring to the 93+ style and replaced the EPC solenoid in the trans. The problem is, a very harsh and drawn out 1-2 shift. Especially the first shift after turning the truck off and driving it again. The rest of the shifts are good. Any ideas?