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E36 alpha-n ignition question

Posted: Wed Jul 05, 2023 11:41 am
by Omniscient
I have a Euro M3 with Schrick cams and an airbox using a modified DME file.

I’ve just been going on what I’ve read by searching this forum but I haven’t been able to find an answer to this question which is - if the MAF is removed and I’m using an expanded MAF failure table for fueling, where is the DME getting the calculation and metering for ignition timing?

The table works and traces but where is the cell indicator coming from if MAF is disabled?

Re: E36 alpha-n ignition question

Posted: Sat Jul 08, 2023 10:34 pm
by olafu
In M50 engines the TPS / RPM based "Alpha N" map produces similar load signal like normal MAF based operation. So, this Alpha-N map affects to ignition also.
Fuel maps are still in use like normal MAF based operation.
I think this is similar in M3 ecu.