Sorry to hear you're having problems with this. I'm sorry to say that, ignition spikes are too thin for the ADC-11 unit to detect.
The ADC-11 can achieve 10,000 Samples per second in Fast-block
mode. Which equates to 100us; an ignition spike only has a width of about 20us. This means that the software is likely to miss the trigger point although occasionally it will hit it (which explains why you have achieved one trace).
If the wave form has a leading edge which remains elevated (ie - it stays above 2kV throughout the duration of the ignition signal, like this one), then you could trigger off a much lower threshold ... but bear in mind that your readings will always have an error up to 100us, and you are unlikely to see the spike on your screen.
(The recommended Automotive unit is the ADC-212/3
, which is more than capable of triggering off the trace in question).