i have a 96 chevy 1500 with 305 engine automatic ,i was wondering if any know how to tell if a pressure regulator has gone bad or is weak. .is there a test to check it or is it not checkable? i have notice that when i fill up on an empty tank there is no air pressure release when i open the fuel cap before i would always hear it when i open it . i have change the fuel pump about a 8 months ago and the fuel fiter 2 weeks ago. i have notice that when i turn the truck off there is a release sound coming from the engine like if some kind of pressure was release. not like a vaccum leak but a pressure leak. the only thing that i do remember is that after i change the fuel pump my truck after runnning about 10 min lack power and the rpms drop it would not do it all the time but now it is. if anyone has advice let me know.

 

I feel like some of the problem has gone away . I change the fuel pump again and it has made a big difference. But now I think I am having a issue with the throttle has an one ever had a problem with a sensor or the body itself. The is on the same truck.

 

Throttle is not sticking it feel like it loses power slowly then if I take my foot of the pedal and hit it again the truck picks up fine. The it starts to lose again power and feels as if the engine is slow low RPM s but if I take my foot of again it has power. The truck runs fine and has power. I don’t know if it can be a Crank Position sensor or Throttle Position sensor. I have no Check Engine Light, is there any way to check these sensors? The only thing I have notice is that at a stop light the truck has a misfire, but if the truck is at idle it runs smooth. I need to get a smog check and I don’t know if this will affect it. This is on that same 96 chevy 1500.