Car feels like it runs well. Took it to a local shop for fine tuning on their dyno with excellent results (ok, excellent results for a N.A. M10 anyway) - short video at the following link:
http://youtu.be/yr_LMgSI7Iw
Known issues that I am working to resolve:
- erratic CLT sensor readings (grounding issues?)
erratic o2 readings (grounding issues?)
o2 sensor reading lower the dyno operators tail sniffer
intermittent complete power failure
coils overheating affecting ignition due to heat from header (only an issue in heavy stop/go traffic - heat shield on the way)
The power failures are the prime concern right now. They don't seem to coincide with any particular event - no bumps or jolts, no hard acceleration, cornering or braking. They have all occurred during cruising. I can drive for many miles before it occurs. I think the longest drive has been 30 mins/30 miles before it first occurred. No power outages during the dyno tuning (3 hour session) or any time prior to it. It was only after the dyno session that I moved the LC grounds to the chassis, and that's about the only change I can recall that I made before the power failures started. I will be cruising anywhere between 50 and 80mph and suddenly it feels like I removed my foot from the accelerator pedal - gradual loss of engine RPMs until it dies. I coast and pull over, turn the ignition off, turn it on again and it fires up immediately like nothing happened.
I have captured datalogs when a power failure occurs, and the logs show voltage dropping as seen by MS. Battery appears to be charged and charging properly. Alternator is an reconditioned upgraded 85amp unit (factory is 45amp). I do not (typically) see any sync loss during these power failure events or at any other time.
A loose connection is the most obvious cause for power failure (still checking), but the fact that the car starts right up again after a power failure suggests that it could be something else.
- Am I really suffering a power failure or is the voltage drop seen by MS a symptom of something else?
Is there anything else in my MSQ/logs that stands out as needing attention?
Colin