COP secondary waveform, using 15" wyze probe

Hi,

I have a 2010 Honda element (2wd, LX), which feels like there is a misfire upon moderate throttle while driving. Also, there is occasionally a hesitation when starting off from a dead stop (like at a stop light). The car runs perfectly otherwise.

I am using a picoscope 2405a, with a recently purchased 15" wyze probe. I'm trying to look at the secondary ignition to troubleshoot this car, but the waveforms I am getting are not making any sense to me. I will attach them here.

They were all taken individually, with a low, descending trigger (I initially thought the waveforms were inverted). They were all taken during a throttle snap.

1. The last frame in each capture should suffice for analysis. The section where the voltage initially drops, and has initial oscillations, I am perceiving as the coil charging event (dwell time). It drops way low, in comparison to what I'm seeing as the spark event (the high spike in the middle). I'm surprised to see the voltage spike that low, and wondering how that is possible.

2. I am perceiving the spike in the middle as the spark event (again, this looks way different than anything I've seen from ScannerDanner, or otherwise). The spark link looks long, but perhaps I'm looking at a stretched out view, and need to use a different horizontal time-base.

3. After the "spark-line" in the middle (right after the vertical peak), I see no "last-second" increase in voltage (the hump at the end of the spark-line). Which I understand could be interpreted as a shorted coil. The problem is, all four coils look pretty much the same, and the car idles fine, without any misses. There is no "bump" at the end of the spark line during idle either (I'll include the capture of a coil secondary at idle as well).

4. The "turn-off" oscillations, or at least what I'm perceiving as turn-off oscillations, seem very exaggerated vertically, in comparison to the spark event. This would normally suggest maybe a lean misfire, however why are they going so far into a negative voltage, with respect to the height of the spark event? This happens at idle too, I think. But the car, idles smoothly, and other than the misfire upon moderate acceleration, seems to run perfectly. How could it be possible that all four coils are shorted, and the car runs so smoothly at idle, low load?

5. Many of the frames before frame #32 seem to be missing a spark event entirely, however the car idled perfectly while taking these waveforms. Is this just the nature of the beast when getting secondary waveforms with a capacitive pickup? Or is it just really tough to find a good spot for the probe on some vehicles?

I think I need help understanding this waveform. Either I am doing something wrong, or the tool is not working as expected, or Honda is doing something really strange with their ignition. Perhaps I just need more practice. Any help would be greatly appreciated.

Thanks in advance!

P.S. -- no check engine light.
The waveforms I'm referring to in this post are called "elem sec ign cyl x thr snap.psdata", but I will include some current ramps I've pulled in the past also.

Curt

I have been searching for similar captures but found nothing, using a probe looking at some COP coils even when working properly can give pretty unique waveforms and I think this is case here.

I think you are getting false triggers, under the hood of car is a very hostile noisey electro magnetic environment you need to raise your trigger to a point well above the zero volts axis to get reliable secondary captures.

Ok, thanks for the reply. I thought I was going crazy there for a bit.

I will try it again with a hantek COP extension and pickup (HT25), and hopefully have some more "normal" looking waveforms to look at.

Thanks!

Curt