Misfire

Had a 2006 ( I think... ) Ford Taurus come in the other day with a misfire. It was random but happened often enough it could easily be observed. Misfire happened at idle and while driving. P0302 stored.

Clear-flood cranking was consistently even so I didn't perform a relative compression test.

Using a Pico I graphed exhaust pressure at tail pipe ( for synching the misfire to the waveform ), fuel injector voltage cylinder 2, primary coil current parade, secondary ignition cylinder 2.



Red is primary, blue is injector, green is secondary, yellow is exhaust pressure.

This is zoomed in. Oscillations during primary turn-off led me to perform an ignition tune up due to a suspected failure of plug wires.




Performed tune up and all is good.

Cool! Thx for sharing. Don't wanna be an ass but you can save your files on Pico as jpg. Much better quality then taking a picture. Keep em coming

Thanks for the tip. I'll try that next time. Doesn't make you an ass. An ass would know but not say anything.

What would be awesome is if we could upload the actual Pico waveform file so anyone could view it in their scope software. That would be great for reference waveforms.

EricGoodrich wrote: What would be awesome is if we could upload the actual Pico waveform file so anyone could view it in their scope software. That would be great for reference waveforms.

Maybe this?

Noah wrote: Tyler turned me on to Scanshare.io
You can upload your data pids there and just put a link in your post for anyone interested to have a look.

It is worth remembering that any Windows 8 or 10 computer will save a screen shot with "Ctrl and Prt Sc" or you can load a free program called "Greenshot" on just about any Windows computer.

Andy.MacFadyen wrote: It is worth remembering that any Windows 8 or 10 computer will save a screen shot with "Ctrl and Prt Sc" or you can load a free program called "Greenshot" on just about any Windows computer.

Thanks but for some reason that didn't work for me. Holding the Windows key and pressing print screen did. The image was saved automatically in my pictures folder.

I appreciate the help guys. Now I can upload pictures that can actually be seen.

For Primary Ignition Waveform; we have to back-probe at Power Feed Wire (B+) or at Ground Wire?
3or4 Wires COP; Signal Wire just shows trigger On-Off? it doesn't form Primary Waveform?
For Secondary Waveform; we have to use HighTension cable to see the Waveform?

MuhammadAli89 wrote: For Primary Ignition Waveform; we have to back-probe at Power Feed Wire (B+) or at Ground Wire?

Back probe the coil GROUND. When the control is turned off, you will see battery voltage. When control is switched on, the battery voltage seen will drop to zero as the coil charges. When the control is switched off again, the magnetic field inside the coil will collapse, creating a voltage spike of about 400v.