MoTeC Global Forum

Hi,

So i got a problem with a particular engine. I have 3 engine blocks from a Suzuki GSXR600 and one of them won't get higher than 8000-9000RPM.

The other 2 engines will cut at 14500RPM without any kind of problem, but this won't.

I'm leaving here 3 videos so you can see how it behaves just prior to die when we hit the throttle and will reach 9000RPM:

https://www.youtube.com/watch?v=rpkYvJeAVJo

https://www.youtube.com/watch?v=BONVBRdPGKs

https://www.youtube.com/watch?v=WLl5L6yMGe8

Seems clear that we have a Sync Error but the OverRPM error and the Inj Duty error are confusing me.

Any ideas?

Thanks!

If you have a trigger issue it will often cause the over RPM and Inj Duty errors at the same time - this is because during the trigger error the ECU 'sees' an exagerated RPM so it will increase the duty cycle proportionally (to the point that you run out of pulse width).
To confirm you could do a pull like this whilst logging engine RPM at the highest rate when you look at the log you will probably see some spikes to a very high RPM where the error occurs.
It could be a sensor dieing, a noise/wiring issue or a setup issue like the sync edge too close to a ref edge but I would need more info about the trigger setup on these engines to help much further...
Can you post a ref/sync capture? - just at idle will do.

AdamW wrote:If you have a trigger issue it will often cause the over RPM and Inj Duty errors at the same time - this is because during the trigger error the ECU 'sees' an exagerated RPM so it will increase the duty cycle proportionally (to the point that you run out of pulse width).
To confirm you could do a pull like this whilst logging engine RPM at the highest rate when you look at the log you will probably see some spikes to a very high RPM where the error occurs.
It could be a sensor dieing, a noise/wiring issue or a setup issue like the sync edge too close to a ref edge but I would need more info about the trigger setup on these engines to help much further...
Can you post a ref/sync capture? - just at idle will do.

Hi AdamW and thank you for your help.

I would say the sync sensor (the proper sensor or the configuration) is failing because when the engine starts to behave strange, diagnostic errors about sync signal appear.

I wouldn't say the problem is the ref sensor but you were right when you said that logging the RPM shows strange values such as 28000RPM or -26000RPM.

Anyways I'm thinking that a ref reading failure would lead to a missed sync signal, and therefore the ECU could think that the sync is failing instead of the ref.

I'll take a capture in 1-2h and will come back with it.