MoTeC Global Forum

Hi, my LS1 is only running on 4 cylinders, the timing order is 1 8 7 2 6 5 4 3, it runs wasted spark so 1+6 8+5 7+4 2+3 are grouped. The exhaust only gets hot for 1, 6, 2 and 3 (notice the link to the wasted spark groupings). I have used the check in the software to check the spark and injectors, and everything works when engine is not running, I checked the compression and this was all good and consistent. I checked the wiring to the coils and this is OK, ie no breaks. Based on the wasted spark groupings it looks like an ignition issue but I can't find it. I have changed the spark plugs, spark plug leads, and injectors. Any ideas?

Both Injector and Ignition channels fire in sequential order from first firing event after missing tooth. Make sure wiring is correct. With 18726543 firing order injectors are wired cyl 1 =1, cyl 8 = 2, cyl 7 = 3, etc., same with ignition 1-6 = 1, cyl 8-5 = 2 etc.

Post cal file.

thanks, I think the wiring is correct, I checked the wiring diagram against the actual wiring, all ok,
when I run the test output option under the utilities menu all the injectors and the spark plugs work as they should
I can't attach the config file as extension m84-12 is not allowed, any ideas?

zipped version of the config file attached

Only other thing I can suggest is verifying you are using the correct ref/sync mode for the cam/crank trigger setup you have installed.

Looks like the gen 3 24x crank trigger has special wiring and setup considerations-

viewtopic.php?f=11&t=356&p=1772&hilit=ls1+crip#p1772

Thanks
The number of teeth on the crankshaft reluctor ring was set at 12 so I changed it to 24 as per the link supplied
This caused the the engine to backfire, run very roughly and it would not idle but all cylinders except 7 and 8 were firing
When the number of teeth is set at 12 it idles and run reasonably smoothly but on 4 cylinders as above

Any other ideas

It really sounds like you have the ignition wiring in cylinder number order, not firing order. This is a common mistake for folks wiring a MoTeC for the first time. You can swap pins at the M84 connector to correct this.

David
I have doubled checked the wiring and the timing order
The coils and injectors are all correct, I used the Test Outputs option under the Utilities menu

Can this be escalated to Motec? There must be other things to check

I did add code 19 to dig in 1 and this helped but still missing cylinders 7 and 8

Thanks
Tom

Sounds like you have wired the REF/sync incorrectly.

Which ref/sync mode have you used? Multy tooth (2) or the special LS mode (23)?

They require different ref/sync wiring.

I'm using code 23, crank sensor going to ref/sync and cam sensor going to dig in 1

As per the motec T24 spec