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Fuel cut at idle startup momentarily

Aaron K

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Attached are my configuration and a log file for a startup on my M62 v8. I have a fairly low RPM limit set right now to prevent overruns when getting it started, 3000 RPM. Open loop idle.

I'm seeing two things I can't explain at the moment I could use a second look at in my configuration:

1. It starts to fuel cut right at the beginning around 2000 rpm, which should be low enough to prevent this? It eventually stops fuel cutting as the engine speed settles down.

2. Maybe related, the dwell time is going between 2.0 and 1.4ms even though I have the table set so it should be a constant 1.8.

Fuel pressure is currently vacuum referenced.

The other thing I'm seeing, that may be outside of the ECU at this point, but I'll mention anyway is that my 5-8 cylinder bank is showing richer (Lambda 2) than the 1-4 cylinder bank. I can't explain that yet. The injectors were cleaned and flow tested before installation.


BMW_E24_M62.pclx fuel cutting at idle.llgx

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2. Drift on the dwell times is because the idle ignition had to advance/retard -- and the ignition dwell would then not be immediately compensated. That is fairly normal.
I suggest 8ms from dwell from 7V, then interpolate in between to about 2.5ms at 14V

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