Need help with interpreting coil wave form

Hi guys I need some help what is this wave form telling me? It’s a cop wave form from a 2009 Nissan Sentra 2.l I’m trying to figure out why it’s missfiring I have access to 3 out of 4 coils with my paddle probe. Most of them can’t be removed without removing the intake manifold. The only one I can unplug is cylinder 4 it has a rpm drop so I compared 1 and 4 they look totally different I’m just not sure what’s causing it Thanks 

Unfortunately, it is not always possible to capture a usable secondary waveform, with COP coils. The Asian market, especially, has more insulation/shielding in their COP's that prevent capturing a usable waveform.

Why do you say it’s not usable? In the two photos one is the one I think is having an issue the other one is the good one.

I say that because neither of those waveforms show any good characteristics of a secondary ignition waveform. There is no distinguishable dwell time, no firing Kv spike, and no distinguishable burn line.
 

I think that you would benefit more from a coil current waveform.



 

Ok thanks I appreciate the reply I started working on cars with pretty much no knowledge of cars I’ve been working on cars 8 years Now . I’m trying to get better with a scope and wiring. A lab scope seems to be a very helpful tool once you learn what your looking at. I’ve already had it help a lot just looking at pcm wave forms.

The two waveforms do not allow (me) to do any meaningful diagnostics. They seem to be taken at idle at almost 900 rpm.

With these coils buried under the intake manifold it is next to impossible to put the paddle consistently into the same position on different coils. You always can check the coils and injectors control signals at the pcm side and current consuption at the correspondig fuse.

You may identify misfiring cylinders/cylinder contribution by canceling out specific injectors and or coils with your scanner.

Looking at dtc's and freeze frame data (check mode 6 data as well), misfire data, fuel trims etc can be very helpful chasing down misfires.

Ok thanks. I’ve just started using a lab scope so I don’t know wave forms. Ya I’ll probably start with a current ramp test next. I looked for miss fire counters could not find any also tried 2 scanners could not get much data I might try another scanner if I don’t find anything with the current ramp test.