I have a 93 Sierra 1500 with the 5.7L V8 and it runs and idles find in neutral or park and when it is cold. When in gear under any load on the engine and once it gets barely warmed up the engine will start to sputter and backfire intermittently. The RPM's jump up and down by a couple hundred as you accelerate and then sometimes the engine drops out completely and even back fires before immediately regaining power. Sometimes it just seems as if it is starving for fuel.
But as soon as you put it in Nuetral the engine revs just fine!
I have no clue where to start. I can replace parts but diagnostics are not my thing.Please HELP!
you should scan the engine and see what the fuel is doing and look at your coolant temp sensor too. With a scanner on the truck and watching your data stream you can see if you're running lean or rich. Or if the fuel system looks good and maybe it's an ignition problem.