My 2005 M3 has been to one mechanic and the dealership - nobody knows why it’s not starting. The problem appears to be too much gas is being pumped from the injectors. Everything else looks good. I have had some phantom electrical issues in the past where my sunroof will start to move on it’s own. Could it be un/related? Could it be the the drive shaft sensor? I would greatly appreciate some feedback and guidance
Too much gas from the injectors could be caused by a defective coolant temp sensor for the computer, where the sensor is telling the computer the coolant temp is at -40 degrees.
Mazda 3 or BMW M3? In either case, I presume it is cranking ok, but not catching and running. Tester’s idea is a good one, the injectors might be being double pulsed b/c the computer thinks the engine is very cold. Or the outside temperature is very cold, due to faulty sensors. Another idea, maybe there’s no spark, but gas is still being injected, that could make it appear like too much gas is in the cylinders, when the problem is really no-spark. That could be caused by the crank sensor, but that would usually throw a diagnostic code. I presume those have all been read and nothing there.
A third idea, a wild guess, but one I’ve had before, if this happened immediately after some service or diagnostic procedure, that procedure might have dumped a lot of gasoline into the cylinders. In which case the engine is so flooded it will never start until the plugs are removed and time is allowed for all the gasoline inside to evaporate out the spark plug holes.