1992 chevy 1500 wont do high rpm's

[Megaflaxman]

I have a 92 chevy pick up 5.7 with 159,000 miles. The truck runs and starts great but shortly after I bought it 3 years ago it developed a sort of misfire at higher rpm's, it's fine if I drive it normally but if I try to pass someone it will downshift then fall on it's face, (spit,sputter and slow down). some times I can feather the accelerator and it will come back again. I normally don't drive the truck in the winter but this week I was forced to use it and the cold weather is seriously affecting it, it took forever to get it up to 70 mph after getting on the highway. once up to speed it will do 75 all day without an issue.

I've replaced the plugs, wires, pulled the throttle body and cleaned it as the port for the pcv valve was plugged solid with carbon. I have not replaced the cap and rotor as they seemed to look fine. I have not checked the fuel pressure because it will break the tires loose upon take off and I don't think that would be possible if the pressure was low, would it?

[SleepyHead98]

Sounds like you got a sensor out. Have you checked the engine codes?

[Megaflaxman]

Didn't think there would be any codes as the service engine light is not on.

[j cAT]

with the use you do I would replace the fuel filter. you use fuel stabilizer ? if not then you may have to remove all the fuel and replace with fresh.

the rotor/ cap and checking the distributor shaft for any wobble is also needed . if it moves then it's trash.

[WBR54cal]

Check to see if the distributer cap is cracked.

[thegreenhornet95]

Have it ever had the distributor and cap replaced.. i had a similar problem with my 1995