I have a 1989 chevy silverado 5.7 tbi. The I'm having hesitation problem mostly when I try to drive it but some times in idle. I have no service light on so the truck isn't giving me any codes. The problem that I was I lost my spark. So I replaced both coil ignition modular and the ignition modular. Truck started first crank. I have replaced my spark plugs and wires. My timing seemed to be 180 degrees off. Now im top dead center. I have just placed the fuel filter. Took the truck out for test drive. Was driving 30 mph. She seemed pretty good but at times she was hesitating but not as bad. Can you give me some other leads

 

main thing is to check your grounds and clean them. also does it act "OK" when the engine is cold?

 

Yes she starts really good just hesitates while driving. Sometimes when I let it run she hesitates and same when I the truck

 

So many possible causes.. check out this link describing similar symptoms. My gut tells me to lean toward an intermittent electrical short - a wire where the insulation has worn thru.
https://www.chevytalk.org/fusionbb/s...hp?tid/304236/

 

yeah i would start with cleaning the grounds even the main battery ones.