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Trying to track down a misfire on my 95 (OBD1) Silverado 5.7 TBI and am having issues getting a reliable spark trigger so I can start looking at intake and exhaust waveforms to narrow down which cylinder is having issues. I'm using a Hantek HT25 probe and I just can not get a solid repeatable ignition waveform for reference on really any cylinder it seems like, I did verify when I remove individual plug wires at the cap the spark looks good and jumps a good gap on all cylinders. I have absolutely 0 experience trying to scope a distributor type ignition system and am really not sure what I'm doing wrong or if maybe the plug wires are too insulated to get a good signal. I also don't have any kind of good sample waveform either. Has anybody ran across this before? Is there some other way I could get a reference signal to be able to discern which cylinder is what? I will also say I had a heck of a time getting my timing light to flash when I set the base timing a couple of years ago and ended up having to go to the ignition coil wire.
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