MoTeC Global Forum

Hello

I need to use M84 on a 4-cyl 4-stroke engine, which has no camshaft signal. Its crankshaft signal is 18-2 per rev.

Now I set the "cylinder number" as 24. But which kind of "Ref/Sync Mode" should be chosen, Two missing twice per cycle or two missing once per cycle?

By the way, how can I wiring the injectors to M84? Each injector has an injection output as firing order? or injector 1 & 4 to one ouput injector 2 & 3 to another?

Thanks a lot~

The Ref/sync mode should be 2 missing once per cycle as the engine will be operating in group fire mode.

Injectors are wired as normal using 4 outputs.

Be sure and set the firing order correctly as well and set it to 2 coils for waste spark. Ends up being semi-sequential, injectors will batch fire twice per cycle every 360 degrees. So if firing order is 1-3-4-2, your ign channels will read cyl1 (1 and 4)and cyl 3 (2 and 3), and injector firing will be 1+4, 2+3, 1+4, 2+3 every 180 degrees. Injector and ign phasing will be normal on one of the pulses and 360 off on the 2nd pulse. Per cyl inj trims still available.

Scott@FP wrote:Be sure and set the firing order correctly as well and set it to 2 coils for waste spark. Ends up being semi-sequential, injectors will batch fire twice per cycle every 360 degrees. So if firing order is 1-3-4-2, your ign channels will read cyl1 (1 and 4)and cyl 3 (2 and 3), and injector firing will be 1+4, 2+3, 1+4, 2+3 every 180 degrees. Injector and ign phasing will be normal on one of the pulses and 360 off on the 2nd pulse. Per cyl inj trims still available.

Thanks for your reply~

So if the firing order is "1-2-4-3 ", I should connect the ignition coils of cyl 1&4 to Ignition Output 1 while cyl 2&3 to Ignition Output 2. Is it right?

Vassili Wang wrote:
So if the firing order is "1-2-4-3 ", I should connect the ignition coils of cyl 1&4 to Ignition Output 1 while cyl 2&3 to Ignition Output 2. Is it right?

Yep.