I have a intermittent running problem and suspecting an ignition problem. Can someone comment on this waveform (dropouts) as to whether this is an actual issue or just a glitch with the amp clamp? I suspect its just the amp clamp - thoughts?

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Looks like the glitch can be caused by a break in the amp clamp's cable into  the amp clamp.

I thought possibly but can't seem to duplicate it checking anything else.

Are you able to repeat the results after zeroing the amp clamp?  What about connecting a voltage channel(s) to confirm what's going with the circuit?

Was this measurement taken at or near the coil where the coil itself is the only possible load in the circuit?

TrevorSchlientz wrote on Aug 21^st, 2024 at 1:00pm:

What about connecting a voltage channel(s) to confirm what's going with the circuit?

My thought also.

The rare time I did see it there does not seem to be any corresponding fault in primary voltage that I was also hooked up to. The measurement was taken near (about 4 inches away from the coil). Zeroing the clamp did not seem to help. Must be the amp clamp

James H wrote on Aug 22^nd, 2024 at 5:13am:

The rare time I did see it there does not seem to be any corresponding fault in primary voltage that I was also hooked up to. The measurement was taken near (about 4 inches away from the coil). Zeroing the clamp did not seem to help. Must be the amp clamp

If the clamp were defective I would expect it to show up elsewhere too. Not just trying to measurer this one coil on one machine. 

Out curiosity, what current probe are you using? Is it an entry level or is it a more premium probe? I ask because the more economy probes have less shielding which leaves them susceptible to outside interference.

Also, just had another odd thought. What if the vibration of the probe cause the jaws to open slightly while in use? I've had it before where a wire I was testing was too taught and would pull the jaws open.

Regardless, if the probe were faulty I would expect that you'd experience issues with it regularly.

Pico TA018. I know if its up close to the coil then the amperage reading is wildly inaccurate. I am kinda at a loss cause I have not seen it on anything else.

James H wrote on Aug 22^nd, 2024 at 8:48am:

Pico TA018. I know if its up close to the coil then the amperage reading is wildly inaccurate. I am kinda at a loss cause I have not seen it on anything else.

Try putting the voltage trace with it. That may give some insight.