Hi,
I have a 88 k-1500 350 auto. The truck backfires through the intake and exhaust. Also has alot of hesitation when driving down the road at constant speed, or while climbing a hill. I have replaced all the sensors with ones that i know work, rebuilt the throttle body, put new distributor, cap, button, ignition module, pickup coil, wires, plugs, o2 sensor, fuel filter, throttle position sensor, ignition coil, and timed it. My next course of action is going to be to replace the wiring harness and computer out of another truck into it. Does anyone have any ideas what would cause the engine to do that?
Thank you,
Rayswizard

 

Any black smoke out of the exhaust? Could be temp sensor. Sure you put plug wires in correct order, or a vacuum leak . Need to check close on vacuum leak.

 

do a compression or leak down test if typically backfires out the intake are caused from a lean condition back fires out the exhaust would be from a rich condition. before spending money on wiring harnesses and computers i would be checking to make sure that you don't have any Burt valves, also check for clogged cats.

 

I have checked the plug and wire order 3 different times. Its correct. It doesn't have a cat on it. I haven't done a compression test yet, but as soon as i get my gauges back, ill check for leaks. I haven't checked the temp sensor, thats about the only one. Thanks guys i'll post the results.
rayswizard