Engine Performance problem
2000 Chevy Silverado V8 Four Wheel Drive Automatic 160000 miles
My 2000 Silverado 1500, 4x4, 5.3 L, has an engine miss. It miss fires upon acceleration. The " check engine soon" light is on at all times. When the engine is cold it starts easily, when it's hot it starts hard. I have replaced plugs and wires and put in a new air filter. I have checked the PCV valve and it was fine. Upon inspection of vacuum lines, I noticed gas coming from the vacuum port on the fuel regulator. When probing the EGR valve, I had an open circuit in the valve position sensor. I don't know if this trips the " check engine soon" light or if this is causing my performance problem. I also have a plug that keeps fouling on the #4 cylinder. I have switched the coils around to check it and it continues to foul. I appreciate any help that you can give me.
Did you replace the regulator to correct the fuel leaking into it? Certainly an open circuit in the EGR position circuit can cause a fault that will illuminate the check engine light. If after correcting these issues, does the check engine light come on, does it flash? Have you been able to determine what is fouling #4 plug(oil, water, fuel). You don't mention a code, this should indirectly relate to the fault. If #4 is fouling and causing a misfire, you may have a P0304, or P0300. One of which(P0304) would be a control issue, a P0300 general misfire detected could be anything from a spark plug wire to a mechanical issue. Have you tried checking spark at the #4 plug, and swapping #4 plug with another cylinder? Also listen to the #4 injector with a stethoscope or long rod to act as one, and compare it to others. If you can, find out what code is coming up and setting the check engine light.