Temporary rough idle
- Thread starter flybobbie
- Start date
Well disconnected mass air flow connector, from cold, engine started normal, straight to fast idle and slowly dropped to 600.
No hesitation or wobbly rpm, even engine was smooth.
Have tried cleaning in the past, looks like just buy another.
Well ordered a VDO Continental.
See if that cures the problem.
No hesitation or wobbly rpm, even engine was smooth.
Have tried cleaning in the past, looks like just buy another.
Well ordered a VDO Continental.
See if that cures the problem.
Fitted new sensor.
Has made a difference, just watched some videos i made. Not jumpy, but just doesn't seem to do what it has done in the past.
Normally goes to 1200 smoothly then slowly falls back over about a minute as it warms up, to be stable at 600.
Runs slightly better through all other rev. range.
Did notice when alternator kicked in it shot to over 15 volts for 3-4 seconds before settling at 14.7, at which point idle stabilises.
All a bit odd.
I think i need to check battery volts before the next start.
Has made a difference, just watched some videos i made. Not jumpy, but just doesn't seem to do what it has done in the past.
Normally goes to 1200 smoothly then slowly falls back over about a minute as it warms up, to be stable at 600.
Runs slightly better through all other rev. range.
Did notice when alternator kicked in it shot to over 15 volts for 3-4 seconds before settling at 14.7, at which point idle stabilises.
All a bit odd.
I think i need to check battery volts before the next start.
I have watched the volt meter whilst driving and it never varies from 14.5-14.7 volts..
Perhaps it varies the current.
But if the battery is ageing, and BMW docs suggest at 5 years an agm battery is only 80% new capacity, the system might just be charging all the time.
I'm going to try and clean the vanos filters later.
Interesting i have a small motorcycle battery that needed charging. I tried a 0.6 amp trickle charger and it wouldn't charge.
Tried a 4 amp car charger and it charged up.
Shows that batteries need some amps to get charging if low.
I wondered what would happen if i re-register the old battery, whether the system would charge it at a higher rate.
The battery might be more robust to charge than BMW give it credit.
Perhaps it varies the current.
But if the battery is ageing, and BMW docs suggest at 5 years an agm battery is only 80% new capacity, the system might just be charging all the time.
I'm going to try and clean the vanos filters later.
Interesting i have a small motorcycle battery that needed charging. I tried a 0.6 amp trickle charger and it wouldn't charge.
Tried a 4 amp car charger and it charged up.
Shows that batteries need some amps to get charging if low.
I wondered what would happen if i re-register the old battery, whether the system would charge it at a higher rate.
The battery might be more robust to charge than BMW give it credit.
