Testing ignition coil output with oscilloscope

[190EVAN]

Hello, I’ve got a major lack of power with my M119. It’s an early KE motor and I’ve already done loads of service to the car over the years with genuine parts. I’ve gone through the entire fuel system and verified that everything looks good. I now believe I have an ignition issue as I tested the spark output at the plug wires coming from the driver side distributor cap and it is much weaker than the plug wires coming from the passenger side distributor cap.

I assumed after seeing this that I had a bad lead going from the coil to the distributor cap or a faulty ignition coil itself. I have tested the lead and swapped the coil out with a functional replacement and the problem pertains.

I am hoping to hook up an oscilloscope to the coils or the X11/4 connector to get an idea of what my coil output looks like. Has anyone here successfully hooked up to the X11/4 diagnostic connector or used an inductive pick up to monitor ignition waveforms before?

Interested in any diagnostic measures beyond checking the resistance of the coil itself to try and rule it out. My ignition coil resistance are good and identical between both coils.

Car also has new distributor caps and rotors, genuine Bosch albeit I have had issues with them recently on another car.

 

[190EVAN]

Problem solved. Verified that both coils were firing by testing coil output at X11/4 pins 1 and 4 per star wiring and obtained a waveform for both. Noticed the burn line of the set of 4 cylinders that were down was looking rough.

Inspected the new Bosch Rotors I just installed and ohm tested them, passed with flying colors using our Wayne Kerr magnetics analyzer but failed under load.

This is not the first time Genuine Bosch parts have failed me on these cars.