1990 GMC 1500 Pickup Q&A

1990 GMC 1500 Pickup Question: WHAT WOULD BE THE CAUSE? MY TRUCK IDLES FINE IN GEAR IT MISSES BACKFIRES W2DIE?

I JUST CHANGED FROM THE 700R4 BACK TO THE TH400 . ALL GEARS WORK GREAT. IVE CHANGED FUEL FILTER N SPARK PLUGS. ALSO PUT IN A FABBED KICKDOWN BUTTON. DONT KNOW WHERE I SHOULD HOOK UP THE WIRE TO SEND SIGNAL TO TRANNY TO KICKDOWN? -
Answer 1
did this problem happen after the trans replacement? -
Comment 1
Yes it did -
Comment 2
CK YOUR TIMING, FUEL PRESSURE AND PLUG WIRES TO START -
Comment 3
Sorry I've been trunk to change me answer. No it had the problem. On drive him after I paid for it. It showed them signs. Top radiator hose collapsed. I've done my fuel fillter,spark plugs. I'm about to do my tos?? -