I learned a ton from your videos. Time to give back. The upward slope of spark burning PLASMA (instead of flat or slightly down) is a sign of High Resistance (electrical). That is how it is classified abstractly by spark scope professors. This generalization is easier to remember and it is Universal. High resistance can be: increased spark gap (like in your case), bad wires, lean mixture, etc. (As to "gas / turbulence interrupting the spark plasma": it is impossible. Spark plasma travels at Speed of Light. But gas (turbulence) is super-slow compare to speed of light, it is like billion of years to travel on a rocket compared to one second of light travel. ) Keyword here is RESISTANCE. Increased Resistance. Upward travel of spark plasma burn.
Another great diagnosis video. The classes that I go to, online and in person, always demo the same generic secondary waveform pattern from the 70's. I learn nothing from that because the waveforms I'm able to capture don't look like that. I don't know about other commenters or viewers but this is the first time I'm seeing this pattern. Thanks for the explanation and video.
On min 2:09 the multiple spikes after the initial breakdown of the scope capture from cyl 2 could also indicate possible coil or spark plug wire ringing, potential spark plug gap issues or possible secondary circuit problems. Great case study Sadel 👍
Great diag with the oscilloscope waveform Sadel! Good analysis like always! I had not seen this pattern before because usually spark plugs are good and rarely failed unless they are from ebay or fake. Thank you for sharing and waitng for the next one.Take care brother! Good info at the bottom!
I know of a case where the torque converter was destroyed due to worn spark plugs, the manual said 105k miles. vehicle had 90k. After transmission replacement had the exact same transmission knocking noise, spark plug replacement took care of it. I think the indexing by torque only works with factory spark plus.
Get the rotkee ukraine made 6 cylinders cop induction sensors, 1 channel gets 6 cop signals and the signal clarity is so good, better than Bernie's ATS vesion single unit. The rotkee is so cheap the price, yet so awesome. Thanks for the video
So what's the conclusion for the year 2024? Preventive maintenance, changing the sparkplugs, requires diagnosis with the oscilloscope? 🙂Give me a break... Owner of the car is a m.o.r.o.n.
Of course it doesn't require the scope, but it is a great opportunity to learn for the next one to come, if I study on this one and can pick out with the scope what the pattern looks like with a large gap, then I have just increased my knowledge
The easiest way to locate an offending misfire cylinder is to scope CKP sensor and coil1 trigger signal as reference. Then apply crank math channel to CKP signal and using coil signal+firing order you find out the offending cylinder.
it gets difficult when off idle because the range settings might not work right for the math channel. I have had one vehicle show me drop out off idle, it was a Mercedes
@@fastbagel You still can find misfire under load up to around 3000rpm ,with crank math channel applied to CKP sensor signal. Above 3000rpm you cannot longer see what is going on as math channel resolution becomes very poor. If you have an email I can send you pictures.
I learned a ton from your videos. Time to give back. The upward slope of spark burning PLASMA (instead of flat or slightly down) is a sign of High Resistance (electrical). That is how it is classified abstractly by spark scope professors. This generalization is easier to remember and it is Universal. High resistance can be: increased spark gap (like in your case), bad wires, lean mixture, etc.
(As to "gas / turbulence interrupting the spark plasma": it is impossible. Spark plasma travels at Speed of Light. But gas (turbulence) is super-slow compare to speed of light, it is like billion of years to travel on a rocket compared to one second of light travel. ) Keyword here is RESISTANCE. Increased Resistance. Upward travel of spark plasma burn.
Thanks for the great information! 👍
Another great diagnosis video. The classes that I go to, online and in person, always demo the same generic secondary waveform pattern from the 70's. I learn nothing from that because the waveforms I'm able to capture don't look like that. I don't know about other commenters or viewers but this is the first time I'm seeing this pattern. Thanks for the explanation and video.
On min 2:09 the multiple spikes after the initial breakdown of the scope capture from cyl 2 could also indicate possible coil or spark plug wire ringing, potential spark plug gap issues or possible secondary circuit problems.
Great case study Sadel 👍
Great diag with the oscilloscope waveform Sadel! Good analysis like always! I had not seen this pattern before because usually spark plugs are good and rarely failed unless they are from ebay or fake. Thank you for sharing and waitng for the next one.Take care brother! Good info at the bottom!
Glad it was helpful!
Very interesting scope pattern, with your explanation being dead-on accurate with what you found that was causing the issue.
Grate video , very accurate scope pattern explanation . well done!! thank you
Glad it was helpful!
Excellent video thanks for sharing
Thanks for watching
I know of a case where the torque converter was destroyed due to worn spark plugs, the manual said 105k miles. vehicle had 90k.
After transmission replacement had the exact same transmission knocking noise, spark plug replacement took care of it.
I think the indexing by torque only works with factory spark plus.
I KEEP LEARNIG NICE DIAGNOSTIC
That's great!
Great work
Get the rotkee ukraine made 6 cylinders cop induction sensors, 1 channel gets 6 cop signals and the signal clarity is so good, better than Bernie's ATS vesion single unit. The rotkee is so cheap the price, yet so awesome. Thanks for the video
Thanks for the info
@DTEAuto u are most welcome.
Great video man I have a P2400 code on my 2016 Mercedes c300, have you dealt with anything similar ?
what's the description for the code
👍
It would have been interesting to see if Mode 6 showed any misfire data. Thank you for posting!
Thanks for the tip, I didn't even think about it
So what's the conclusion for the year 2024? Preventive maintenance, changing the sparkplugs, requires diagnosis with the oscilloscope? 🙂Give me a break...
Owner of the car is a m.o.r.o.n.
The used car shops bring their cars to DTech. Don’t be so fast to comment when you don’t know the entire story.
Of course it doesn't require the scope, but it is a great opportunity to learn for the next one to come, if I study on this one and can pick out with the scope what the pattern looks like with a large gap, then I have just increased my knowledge
The easiest way to locate an offending misfire cylinder is to scope CKP sensor and coil1 trigger signal as reference. Then apply crank math channel to CKP signal and using coil signal+firing order you find out the offending cylinder.
Yes, that is a very effective way to do it for sure
Does that still work off idle? I have only had success doing it at idle with crank maths but maybe I haven’t worked out the settings
it gets difficult when off idle because the range settings might not work right for the math channel. I have had one vehicle show me drop out off idle, it was a Mercedes
@@fastbagel You still can find misfire under load up to around 3000rpm ,with crank math channel applied to CKP sensor signal. Above 3000rpm you cannot longer see what is going on as math channel resolution becomes very poor. If you have an email I can send you pictures.