GM Repair Problems? Ask GM Repair Expert Now.
Hi there, I am Cam. I Am sorry to hear about this issue on your vehicle. This is a common issue on the 4.2L engine. What happens is the system was likely reset because of the battery being remove. Then when it was hooked back up, the adaptations it had learned specifically for the throttle have been erased. To correct this, take the upper intake plenum off, the black box that says 4.2L Vortec. There are 2 10mm bolts and 2 hose clamps. Then clean the throttle plates with a rag and carb cleaner. After that, take the battery cable off and reset the vehicle. This should fix this.Take the battery cables off the battery, hold the ends together for 10 seconds then attach them to the battery and see what happens. This will reset the whole vehicle. And the reset is more about touching the cables together when removed from the battery than having them removed. touching them together its what drains the capacitors and resets the short term memory.
Did that change them?