91 chevy k1500 Ignition/spark issue
 

I have a problem i am hoping somebody can help me with i am stumped. I have a 91 chevy k1500 i changed my spark plug cables and cleaned my plugs, dist,& router started the truck worked great. started it up in morning ran good for 10 min then started puttering. so i changed the plugs cap and router still happening. its very strange it starts fine then it acts like its going to stall almost like its miss firing then comes back its very concetent i guess u would say when it bogs like if it was boging when it hit a certin cylinder. checked my spark on every plug strong coil has strong spark. I have checked the wires there in the right place i changed to tps sensor redid the timing checked the wiring harness i am at my wits end with this. Any help???