Hello all,

I recently rebuild a 91' Chevy K1500 and after a few months of driving it, it started to sputter out. I'll list all the specs below but I'll go ahead and explain my problem. Typically once I reach 4th gear my truck will start sputtering and bogging down. If I put it to the floor it'll accelerate just fine. Cruising is out of the question. Once it starts in 4th gear, it will extend to 3rd, and sometimes even 2nd gear. No matter how fast I'm going. This eventually even turns into an unsteady idle. You can clearly hear the truck cutting out and it acts as though its going to die.

It's a 4.3 v6 bored .30
4spd Granny Low Tranny(bullet proof)
new pickup coil and ignition control module
new distributor cap and rotor
I've checked fuel pressure and even when it's cutting out it stays constant @ 16lbs
new fuel filter
I've checked all the plugs(new ACDelco) and they are fine. The wires are brand new as well(Accel)
I've checked the TPS and it appears to be operating fine. The injectors also appear to be acting fine. I'm out of options and I'm about to take it to a mechanic and pay them a fortune to do something I can do myself. Can somebody pleeeeease help me?! I'm at my wit's end!

 

I also installed a new ignition coil.