arcking
Well-known member
Does anyone have any thoughts as to why an '04 BEW would be requiring a high injection quantity to maintain idle after a cold start? It's my understanding that ECU will adjust fueling as necessary to maintain 903 rpm at idle - in this case of my car, this means around 15-20 mg/st (well over 'known good' engines).
What might cause this? I have a couple of ideas below, but am interested in any other thoughts, methods of testing, or confirmation on ideas below:
What might cause this? I have a couple of ideas below, but am interested in any other thoughts, methods of testing, or confirmation on ideas below:
- Load on the engine
- Drag from 09A triptronic transmission, as hinted at in this thread but not resolved
- Accessory belt - AC compressor, alternator, power steering pump
- Timing belt - water pump, cam, tensioner (have all been changed and no change to symptoms)
- Internal resistance in engine (currently running T6 5W-40, same as known good in same environment)
- Timing - I believe this to be unlikely due to the torsion value being in-spec (and not 0.0), but there's a good read here where a fluke timing issue caused high IQ at idle when cold
- Low compression- checks out good cold and warm
- Nozzle/Injector wear/damage - would a poor spray pattern lead to more fuel being injected?
- ECU reported mg/str doesn't match actual - this seems unlikely given the feedback the ECU gets from the injectors, but I can't say I understand how this plays out.