New;

Mass air flow sensor, coolant temp sensor(hard to reach one), oxygen sensor, throttle position sensor, fuel pressure regulator, all fuses cleaned, new air filter, plugs, wires, cap and rotor. All injectors work fine and don't leak, cold start injector working ok also not leaks, idle air control functioning properly, no vacuum leaks. Car runs rich, all plugs are black, "check engine" light is on, I believe code 3-1-2, computer compensating for extremely rich or extremely lean mixture. I reset the computer numerous times and after each part replacement, takes about 5 to 6 miles of driving to turn on "check engine" light.

Took out computer, found a grey looking piece on computer board burnt out, replaced with same piece out of a Renault Aliance computer. Still no luck. Now locating a used computer to troubleshoot with. Any ideas. After computer changeout is wiring harness replacement.

Car is 1989 with approx 100k on it.

Frustrated but not giving up,