I have a 1995 325i that will crank but won't fire up. I also have a code on the onboard computer of "tail light failure." A friend told me that it could be a faulty brake light switch, due to the fact that the tail lights still work. I replaced that switch, no help. I pulled the back seat and the cover for the fuel pump and had someone turn the power on without starting and heard nothing out of the fuel pump (no pressure build up). I checked the fuse and it is fine (15A fuse). Don't know where to go from here.
Oh, I was told by the previous owner that the fuel pump has already been replaced once.
Crank no start can be a dead fuel pump. Try spraying some brake clean or some gasoline into the throttle body, if it fires, it is probably the pump. The light bulbs all need to be inspected and if any are the brass base type, they need to be changed to the silver base ones like BMW sells, the brass ones will turn that light on. Also check all the connections for heat damage or corrosion.
January, 23, 2011 AT 12:11 AM
I read on a BMW forum that it could be a crank position sensor. Is there any kind of bench test to tell if that has gone bad? I say this because the check engine light on the dash doesn't go away while cranking, which I am told means its not receiving a signal.
January, 23, 2011 AT 12:15 AM
The crank sensor on that model is a passive diffusion type sensor that generates an alternating current voltage, it should be possible to see it generate voltage on a digital multi meter. Did you try my previous suggestion?
January, 23, 2011 AT 12:21 AM
I'll check all the bulbs per your suggestion. As for the spraying into the throttle body, my dad and I tried that once before and it almost fired up. Nothing solid to go on tho.
January, 23, 2011 AT 12:24 AM
Is there a way to power the fuel pump separately from the car's power to see if it is indeed the pump or if it a power supply issue (caused by bad crank position sensor)? I can't afford to spend almost 300 on a pump to replace one that might still be good.
January, 23, 2011 AT 1:13 AM
Power the violet/green stripe wire at the connector, that will run the pump. If it is the pump, let me know, I know where a much cheaper pump can be obtained.