| Select most likely cause ---> | Cause is indicated by these symptoms |
| low system voltage | gauges are erratic - fault is intermittant - |
| EML |
EML warning shown in cluster |
| TCU | TRANS PROGRAM warning shown in cluster |
| Cylinder identification sensor | very subtle, difficult to find problem |
For '91 750il: bank two is not running but no eml light is showing. Initial Checks: Both fuel pumps OK. Fuel is flowing to both regulators ok. Checked the spark on bank 2 and all wires have ok spark. A fault code is stored saying that there's a problem with the ignition on bank 2. Viewed the fuel injector pulsewidth and it's at .4 ms and shows the load being at 0 on bank 2. other side has normal readings. Also the scan tool says the the ignition fault would cut off fuel injector pulse width. Tried swapping coils, dme and maf, nothing changed. Solution: The spark plug on # 12 was fouled causing the signal from the cylinder identification sensor #2 (bank 2) to be skewed because it is driven by cyl. number 12 spark plug wire for info to the DME. It thought that it had a dead cylinder and the engine management was cutting off fuel to that bank! |