Engine Performance problem
1995 Chevy S-10 4 cyl Two Wheel Drive Manual 166000 miles
i recently purchased a '95 chevy s-10 that had a new jasper 4cyl engine with roughly 1000 miles on it. The problem is when you accelerate the truck starts sputtering and backfiring like it is out of gas and tries to quit. The more you try to accelerate the worse these symptoms get. Also, the fuel pump has an abnormally loud whine to it most of the time. When the fuel pressure is released, this whine seems to subside and the truck runs fine. I have replaced the air filter, fuel filter, fuel injector seals, fuel pressure regulator, checked the vacuum hoses, exhaust system, spark plugs and wires.