Section 1: Universal Testing Methods p14 secondary

On page 14 of the e-book section one. Figure 4, examples of secondary waveforms.
The very last pattern, right next to the one labeled "no fuel misfire" in the bottom right corner.
Whats going on there????

I always figured that as a failed injector, electrically or mechanically. Saw a very similar waveform recently on a Chevy 5.7L with a stuck closed injector.

Tyler wrote: I always figured that as a failed injector, electrically or mechanically. Saw a very similar waveform recently on a Chevy 5.7L with a stuck closed injector.

I am ashamed that I do not remember that particular one. it is a waveform from the early 2000s
but it was exactly as Tyler described.
Sorry Noah

That's cool, not a problem man! Have you heard the theory about secondary waveforms that says if you draw an imaginary vertical line right in the middle of the spark line, that any oddities on the left side of that line indicate a problem exterior to the combustion chamber (shorted/open plug wires), and that anything to the right of that line indicates a problem occurring inside the combustion chamber (lean mixture, etc)?

Seems to hold up pretty well to the examples in the book. I'm not exactly a secondary ignition guru though

Noah wrote: That's cool, not a problem man! Have you heard the theory about secondary waveforms that says if you draw an imaginary vertical line right in the middle of the spark line, that any oddities on the left side of that line indicate a problem exterior to the combustion chamber (shorted/open plug wires), and that anything to the right of that line indicates a problem occurring inside the combustion chamber (lean mixture, etc)?

Seems to hold up pretty well to the examples in the book. I'm not exactly a secondary ignition guru though

I haven't and that is a great tip to explore! Thanks Noah