[FIXED] 1998 Ford Econoline v10 ignition waveform analysis

Had a couple headaches today and this is one.

DTC p0305 Cylinder 5 Misfire
One of our guys put ten plugs in a few months back, a few of coils over the years.

Went straight for the coils and grabbed a couple of primary waveforms from cylinder #5 and #10, and a current ramp parade.


Here is a couple examples of #5










And this is Cylinder #10 (known good) Pattern didnt really change as much as cylinder 5, and this is what they all generally looked like except the 3 firing events at idle.







Will be taking the plug and coil out tomorrow for swap and inspect, didnt have time today. Any body see anything right away from the captures?

I like that first #5 capture. I think you're gonna find some kind of plug problem. Porcelain is coming apart, or it's badly ash fouled. But I could be wrong. :silly:

Here is the culprit




Well it was in the coil too, both got replaced. The coolant was from a previous repair, and was never cleaned out.

Here is the after shots, first at idle in gear. Second under heavy acceleration. This was an easy one, but learned what a shorting secondary looks like I suppose.

Ah crap, I was a bit off with my guesses. I was kinda right with the plug part? :silly: