Hello, I have a 1991 325i e30 (AT) that isn't starting/stays running.
Following most of the diagnostics that I've read so far with the symptoms of having the engine not turn over. so far I've swapped the fuel pump with a known working one and replaced the fuel and main relays with a new ones. The engine reference sensor is roughly 3-4 years old. Everything powers up and electronics work as normal. Its just the engine won't turn over or stay running.
The other day I first noticed something was wrong when driving about 30-40MPH at about 2-3000RPMs then having the engine choke and watching the RPM's drop to zero then back to normal like nothing had happened.
Today, I got the motor to turn over a few times after changing the relays with new ones, but when I would step on the accelerator, the engine would cut off. When cranking it for those first times, I could hear a subtle thump, like it was the fuel pump or something, not real sure.
I suspecting it to either be the fuel pump, fuel sending unit, dirty fuel filter, the engine reference sensor, or some electrical problems...
I'm going to swap the engine reference sensor tomorrow to see if that may be the cause of the problem.
Open to any tips or suggestions, Thanks in advance.