Hi to all.
I am setting up a VEMS unit on a KTM single cylinder engine. We are using a (modified) stock trigger wheel 18-1 setup. And standard throttle body, VR-sensor and injector. Software version 1.0.78rc2.
Now the trigger setup needs to be verified as we are getting backfires and the engine won't run.
Below our trigger wheel setup and alignment with respect to TDC:
And the following settings:
Now I have measured the VR-sensor signal and compared it to the ignition signal. This is done by wiring a resistor between the ignition coil wires and measuring the signal.
Now by driving the engine with the starter motor we get a reasonably constant 300rpm signal. The Ignition Advance is now measured entered in the Priming, Cranking and Afterstart settings dialog window:
Now we have started with 10 degrees advance and got the following scope picture:
But measuring the timing between TDC and the ignition trigger is measures 29 degrees and not 10 as it should be.
The following is with 20 degrees advance:
But measuring the timing between TDC and the ignition trigger is measures 31 degrees and not 20 as it should be.
The following is with 30 degrees advance:
But measuring the timing between TDC and the ignition trigger is measures 36 degrees and not 30 as it should be.
Comparing these last ones it implies that 10 more degrees of advance only is 5 degrees in reality. How can this happen?!
Has anyone any suggestions...
