Hey all, been battling my 1987 early model 325i cabriolet. Looking to narrow some issues down. First of all - sometimes, when the key is in the START position (cranked), the car will immediately lose all power, with a weird cracking/creaking noise. I checked, and the battery still has 12v. Previous to these electrical issues, I had blown my OBC relay box, and an ECU (melted a fuel injector driver - right side of pins). I have since replaced both of those, and am unsure of why that happened in the first place (maybe from jumping it without removing OBC pins?).
Anyway, when it does run, it runs rich. Burbling, etc. I have noticed that spark plugs 2 and 4 are wet with fuel, which would make sense considering one of the blown fuel injector drivers. Now I am just lost on what to do next. I (presumably) have electrical issues, but to find this, should I start probing ECU pinouts? I have tested resistances on all injectors, and they are within spec. I only got to noid light injectors 5 and 6 (before i got rained on), and they seemed to flicker the noid light consistently. I would assume if the cylinders 2 and 4 are rich, 6 would be too, but the noid light looked good. If anyone has questions, I can provide videos of spark plugs firing, the car running rich, etc.
My thinking based on the wiring diagrams, was that considering this happened in key START position, maybe it is something to do with the ignition switch or power distribution box, but I am leaning towards ignition switch - because the power from the battery goes to that, which goes to the OBC relay box, ignition coil, AND the ECU.
Can anyone confirm if they have had similar loss of electricity or wonky/inconsistent spark or fuel?
Anyway, when it does run, it runs rich. Burbling, etc. I have noticed that spark plugs 2 and 4 are wet with fuel, which would make sense considering one of the blown fuel injector drivers. Now I am just lost on what to do next. I (presumably) have electrical issues, but to find this, should I start probing ECU pinouts? I have tested resistances on all injectors, and they are within spec. I only got to noid light injectors 5 and 6 (before i got rained on), and they seemed to flicker the noid light consistently. I would assume if the cylinders 2 and 4 are rich, 6 would be too, but the noid light looked good. If anyone has questions, I can provide videos of spark plugs firing, the car running rich, etc.
My thinking based on the wiring diagrams, was that considering this happened in key START position, maybe it is something to do with the ignition switch or power distribution box, but I am leaning towards ignition switch - because the power from the battery goes to that, which goes to the OBC relay box, ignition coil, AND the ECU.
Can anyone confirm if they have had similar loss of electricity or wonky/inconsistent spark or fuel?