Re: Something to note re: motor electronics ...... (archive)

Also, keep in mind that the DME will try to copensate for a failing component as best it can. When the component is ultimately replaced, the DME is using old data which will result in poor running. Hard reboots are sometimes needed.

A little while ago I posted a message to which George Mann and Kevin replied suggesting my change in idle characteristics (750iL, vibration and change in exhaust note) could have been due to muffler (backpressure change) or engine / transmission mounts.

Upon further analysis I came to the conclusion that it could also have arisen due to a change in engine management electronics i.e. timing, injection etc. However, this seemed unlikely as the car was actually running (driving) fine.

Thanks to this board I had previously learnt that disconnecting the battery for at least 24 hours would 'reset' some control modules and even resync the throttle motors in a V12. As it turns out this was the remedy for me.

After having the battery disconnected for 2 days, the first time I then started the car it took itself 3 or 4 seconds to 'get its bearings' so to speak and then ran perfectly.......back to normal. No point flutter, beating valves, or idle vibration or unfamiliar exhaust note.

Just thought this might be useful info for future reference. As I said in previous post........don't underestimate the extent to which the DME (with its learning chip) can effect the running of your motor.
From now on I will always try a 'reset' by disconnecting the battery before I venture into more arduous repairs.
Thanks again to all who initially helped with my query.

Regards,
Brian.

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