92 Chevy C1500 6 cyl hesitation under load

chevrolet
1500

#1

I have an old C1500 with a 4.3 V6 and 358,000 miles on it. I cannot afford to take it in to get it diagnosed and repaired (big surprise since I own a truck with more miles on it than it takes to go to the moon!) It was having a problem with a ‘revving’ idle and would sputter when driving down the road unless you pressed the gas so far it downshifted and revved real high, then it would gain speed, but would not maintain speed without the hesitation. Recently, I unplugged the MAP sensor and the idle smoothed out and will accelerate on level ground, but if I have to go up a hill and press the gas more than a quarter of the way down, or so, it has the same problem as before. I replaced the MAP sensor and experienced the exact same problem originally so I know it’s not the MAP sensor. My son is experiencing the same issue with his 94 firebird with a V6 and would like to find a resolution to this issue as we are poor and we really need these vehicles every day. Any help would be appreciated.


#2

Start with the basics. Spark plugs & wires, fuel and air filter, check the fuel pressure, check it for vacuum leaks (not usually noticeable under acceleration, but creates a revving idle).


#3

the biggest problem I’ve seen with these is the hose splitting between fuel pump and the pipe the hose is attached to. you need to do a fuel pressure test. since this is a tbi truck you will need a fuel pressure gauge that will connect to fuel line behind filter. we call this a deadhead test. turn on pump to get fuel pressure. specs are 9 to 13 psi. my bet is that it is lower than 9. good luck. no smoking!


#4

Thanks, where can I get one and what do they run?