ok today i went for a drive then my car suddenly dies and the dash lights wouldnt even light up and the box right next to the ecu by the passenger door made a buzzing sound .sometimes the car starts fine and sometimes i get no power what so ever when i turn the key. i really need help i took the battery and got it tested at autozone and its good . what would cause it to work then not work
Same thing happened to my 92 ls. Check the wireharness around the ecu and my the motor mine burnt from the engine bay to my fuel pump. Give that a try. And always check that mfr could be that
Very similar problem here. One of my DAs dies like this; it will work perfectly fine at times, other times it is DEAD. the hazards, headlights, etc wont’ come on. Sometimes it will give a buzzing sound, which seems like middle to right side of the front cabin. Tried changing the MFR and no workie.
It is a power or ground connection problem, it has nothing to do with the PGM-FI Main Relay, [MFR], the PGM-FI Main Relay supplies power to the fuel pump, [fuel pump relay] and the fuel injectors, [injector relay] both relays are housed in the PGM-FI Main Relay.
The injector relay also supplies power, [signal] to the ECU/ECM and a few engine sensors/valves, [depending on year].
The only “light” in the cluster the PGM-FI Main Relay has an effect on is the CEL, none of the other cluster lights would be effected even if the PGM-FI Main Relay was removed, 94