MoTeC Global Forum

We are installing a M800 in Nissan 350Z race car (VQ35).

We have a problem with sync errors at ~7200 rpm. We are running Ref/Sync Mode 55.

We have put an o-scope on all the inputs to the M800 and there are very clean.

Motec USA has been helping us but they are stumped as we are.

Has anyone had any issues like this?

Thanks..

Are the errors actually causing any problems ?

I got ref/sync errors on a friends Subaru all the time, despite a perfectly clean signal. It never actually had any effect on performance or driving.

Yes the sync error is causing a skip.

Does anyone know what causes a sync error in Mode 55? I believe that in this mode the sync signal is generated by the ecu as both the ref and sync input pins of the M800 are connected the crank position sensor.

chrisoutzen wrote:Yes the sync error is causing a skip.

Does anyone know what causes a sync error in Mode 55? I believe that in this mode the sync signal is generated by the ecu as both the ref and sync input pins of the M800 are connected the crank position sensor.

Maybe you need the screen trace posted up.

If it is a 4-stroke then how it would get sync if the sync is using the crank sensor?

we use mode 35 for VQ37. I think they are the same setup. I recall trying 55 and it not working. You should try ref/sync capture (Utilities) to verify you have ref and sync in the proper inputs. I can't imagine that engine would even run without both in proper inputs; there's not enough info in the crank wheel alone.

pftuning wrote:we use mode 35 for VQ37. I think they are the same setup. I recall trying 55 and it not working. You should try ref/sync capture (Utilities) to verify you have ref and sync in the proper inputs. I can't imagine that engine would even run without both in proper inputs; there's not enough info in the crank wheel alone.

It might run like a wasted spark, and maybe injecting twice in 720, or at the wrong time. But it might work???