I have 1990 Legacy 2WD sedan (210K miles) with serious misfire problems. The car runs ok at an idle, however, when completley warmed up, the #4 cylinder is "firing twice" (according to an electrical specialist) and #1 misses occcasionally. This action completly fouls the spark plugs.I have replaced the plugs, wires, #4 fuel injector, TPS, ECU, O2 sensor, mass air flow sensor, and I have run out of ideas. My local dealership has screwed me over for the last time.....I know nothing about this EFI system but am willing to learn. I just had the top end rebuilt (burnt valve from my wife overheating the car) I havent tried replacing the cam sensor yet....can anyone tell me what to do? This is so frustrating......
Chaz
