Engine misses and backfires - help!
Posted: Sun Jun 13, 2010 5:01 pm
Okay, to start with the engine is an M30 3-litre from a 530i.
The idle hunts up and down, and when driving (all the way throughout the rev range) the engine misses and backfires. It doesn't feel like one cylinder, it rather feels like the entire engine cuts momentarilly. I have so far changed:
Airflow meter (the replacement was OK when I took it off another car 2yrs ago)
Idle control valve
Ign coil
checked the distributor cap - gave it a clean, it looks OK
Checked all hoses for air leaks - they seem fine
Disconnected the TPS sensor - the engine still runs OK but doesn't fix the fault
I am now totally stuck! I have had it in the local garage and the diagnostics code came up with an air flow meter error but I am not convinced.... any suggestions?
Thanks,
Jason.
The idle hunts up and down, and when driving (all the way throughout the rev range) the engine misses and backfires. It doesn't feel like one cylinder, it rather feels like the entire engine cuts momentarilly. I have so far changed:
Airflow meter (the replacement was OK when I took it off another car 2yrs ago)
Idle control valve
Ign coil
checked the distributor cap - gave it a clean, it looks OK
Checked all hoses for air leaks - they seem fine
Disconnected the TPS sensor - the engine still runs OK but doesn't fix the fault
I am now totally stuck! I have had it in the local garage and the diagnostics code came up with an air flow meter error but I am not convinced.... any suggestions?
Thanks,
Jason.