So since I've had my 91, its been giving me a few headaches. The first started when I washed out the engine bay after purchasing it. I got water in the first 2 spark plug tubes which caused no spark on 1 and 2. Misfires, bucking, stalling, no start kind of things. Easy fix, no problem cleaned ut the tubes and put in new plugs.
Then it happens again, this time after a rainstorm (put her away wet), next morning long crank, check engine light on and off, flashing like its got a bad miss. Not spark related as the burn is good, plugs arent fuel covered at all, rule out coils, plugs, or wires. After waiting, cranking, letting it die, trying again, fires up and runs perfect for a few weeks.
Then another rainstorm hits, car does it again. Then back to normal after awhile. Let it sit all this weekend, and it had rained the night before and today. Get in and yep, you guessed it, cranked, died, check engine light on and off, dies. Try it this afternoon after letting it sit all day, no improvement. Actually ended up destroying the guts in my catalytic convertor. So it seems this is a common problem but there doesnt seem to be much documentation on it. Me being a BMW technician, do not want to throw parts at this thing, but it becomes tough to diagnose when the DME wont tell you anything.
So, get car running, unplug cam sensor, car still runs but eventually runs bad and dies (does this regardless, but the key is it still runs). Unplug the crank sensor and crank the car, cranks all day long doesnt try to start. Still starts with the crank sensor plugged in, but cam sensor unplugged. Lowest electrical component on the car is the crank sensor, car does not have splash shields, water can get up there at any time, gets on my belts and causes them to squeal. Crank sensor determines cylinder position for spark and fuel.. see something here? I will replace the crank sensor and report back.
Moral of this story is, be sure to try a little diag before throwing parts at the car (unless you can swap from a friend). And also please report what actually fixed your problem. Ive found tons of threads about m42 check engine lights, and rough running, and either a combination of 100 parts fixed it, or no one ever replies.
Then it happens again, this time after a rainstorm (put her away wet), next morning long crank, check engine light on and off, flashing like its got a bad miss. Not spark related as the burn is good, plugs arent fuel covered at all, rule out coils, plugs, or wires. After waiting, cranking, letting it die, trying again, fires up and runs perfect for a few weeks.
Then another rainstorm hits, car does it again. Then back to normal after awhile. Let it sit all this weekend, and it had rained the night before and today. Get in and yep, you guessed it, cranked, died, check engine light on and off, dies. Try it this afternoon after letting it sit all day, no improvement. Actually ended up destroying the guts in my catalytic convertor. So it seems this is a common problem but there doesnt seem to be much documentation on it. Me being a BMW technician, do not want to throw parts at this thing, but it becomes tough to diagnose when the DME wont tell you anything.
So, get car running, unplug cam sensor, car still runs but eventually runs bad and dies (does this regardless, but the key is it still runs). Unplug the crank sensor and crank the car, cranks all day long doesnt try to start. Still starts with the crank sensor plugged in, but cam sensor unplugged. Lowest electrical component on the car is the crank sensor, car does not have splash shields, water can get up there at any time, gets on my belts and causes them to squeal. Crank sensor determines cylinder position for spark and fuel.. see something here? I will replace the crank sensor and report back.
Moral of this story is, be sure to try a little diag before throwing parts at the car (unless you can swap from a friend). And also please report what actually fixed your problem. Ive found tons of threads about m42 check engine lights, and rough running, and either a combination of 100 parts fixed it, or no one ever replies.
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