MoTeC Global Forum

I have a Ford 427W engine I have retrofitted for EFI (Motec M84). I am using a 4 tooth crank wheel from FAST and have modified my MSD distributor to act as a cam sync.

This setup is a Mode 0 Sync/Ref (one tooth per firing event). The manual states the following:

"For some trigger modes (one tooth per firing) the Ignition Timing is set by the sensor position only. In this case the ECU only controls the timing above 500 RPM."

Am I interpreting this correctly:

I should set my physical CRIP to my desired initial (cranking) timing on my crank sensor. So if I want 12* BTDC initial timing, I should set the orientation of the inductive sensor to trigger at that point? And this is because the ECU won't control timing below 500 rpm (cranking) when operating in this mode.

Thanks!
Jacob

Correct for one tooth per TDC mode, The tooth edge that you choose ( rising or falling ) should be mechanically set to the cranking timing you wish to run.

If you have a magnetic sensor then you should do a screen capture of the REF/SYNC pattern without the spark plugs fitted. Depending on the waveform you then set the correct edge, then mechanically rotate the chopper disk or REF sensor to get your cranking timing.

With a Hall sensor, it does not matter which edge you use.

Thank you! I'll give it a go today.

Quick follow up - This worked well. I set my physical CRIP to 10* BTDC and that's what I saw during cranking. Once the engine fired up, it picked up on the ignition map where I had it set to 13* BTDC.

Thanks again!