I've got a 1989 Chevy C1500. It's got a 4.3L V-6 and a 5 speed with 213,000+ miles on it. Yeah, I hear you V-8 guys laughing about a V-6. Anyway, here's the problem. When I set the timing to specs, 0 degrees TDC, when I step on it or go up hills, it pings really bad. It seems like the ignition advances too far. I've got the timing retarded to about 6 to 8 degrees ATDC and I've got the pinging under control, but its a little sluggish. I don't think its a problem with carbon build-up in the cylinders since the head gaskets were replaced at about 150,000 miles, before I bought the truck. I've replaced the MAP, IAC, O2, CTS, Knock Sensor, EGR Valve and solenoid, timing chain(about 30,000 miles ago) and the fuel pressure regulator. There's no sign of a vacuum leak and it isn't overheating. Also the regular tune-up stuff-cap, rotor, wires, fuel filter, ect. I've even gone to one heat range cooler on the plugs but no dice. This thing almost sounds like a diesel. I've tried different octane gas and no change there either. I checked under the control module and noticed that there wasn't much grease left under it so I wonder if the module could be bad. But everyone I've talked to tell me that modules usually just quit. Is that the case, or could it be malfunctioning. I might be able to get my hands on another to test that theory but I gotta break into my friend's car to get it while he's in jail! So if there's anyone out there with any suggestions(other than getting a new truck or a V-8), or if someone could tell me if modules quit altogether or can m they start having problems, please let me know 'cause this pinging is driving me nuts.