I've been doing this for just over 38 years, and noticed the burn line was too clean. However my guess was a cracked insulator deep down inside the plug which can also do this. Years ago when I attended a Robert-Bosch training clinic where I learned some eye opening things. #1 - Pay attention to the insulator diameter. If the replacing sparkplug is as much 1mm smaller than OEM, you'll likely get a misfire sooner or later. #2 - Lower the sparkplug gap on anything requesting .0.045" or more. This lowers the stress of the ignition system a great amount and improves mileage.

@CartersDiagnostics

3 ай бұрын

Great information. Thanks for sharing. Now I wish I would have measured the cracked plug and compared it to OE. I will the next time.👍

Good work sir, thanks for the education. Always pick-up bits of knowledge from your vids.

@CartersDiagnostics

4 ай бұрын

Thats great. Thanks for watching 👍

Thank you for sharing this, and all the good work you do in all of your videos, I learned a lot. Much appreciated thanks again.

@CartersDiagnostics

4 ай бұрын

💯👍

Great video thanks for sharing

@CartersDiagnostics

4 ай бұрын

💯👍

great diag on secondary ignition and waveform analysis , cheers

@CartersDiagnostics

4 ай бұрын

Thanks for checking in 💯

This was a good one! Nice job!.

@CartersDiagnostics

3 ай бұрын

👍💪

Fascinating stuff Mike. When you asked what might be wrong I was thinking spark plug but honestly i wasn't sure why. In the GM world i came from it was common to find carbon tracked plugs but I don't ever remember one causing a dead miss. It was very hard to duplicate in the stall. Took a test drive with high load at lower rpm to get them to break down. I guess I wrongly thought a carbon tracked plug would have caused the spark line to have broken out at a higher kv compared to known good and have been a bit more violent looking.

@CartersDiagnostics

4 ай бұрын

No two carbon tracks are the same . This one was worse case and easy to find. I honestly think someone cracked it during install. The coil boot was heavily compromised also. So the secondary components couldn't hold the KV . So it produced a perfect downsloping spark and it jumped out early. I've seen some carbon tracks fire half in and half out of the cylinder they do tend to look violent, kinda straight down. A carbon track does offer some resistance to the firing, unlike a direct spark to the cylinder head.

@lonniepeterson-xq3vx

4 ай бұрын

@@CartersDiagnostics Thanks, that extra info really helps.

Great Cause and Effect Video !

@CartersDiagnostics

4 ай бұрын

Thanks for joining in👊💯

I appreciate your efforts million thanks I hope you to explain that on the car

@CartersDiagnostics

4 ай бұрын

Thank you💯

Great job, nice breakdown.

@CartersDiagnostics

4 ай бұрын

Appreciate it!

Thanks for this.

@CartersDiagnostics

4 ай бұрын

O yeah 💯

Great video, thanks

@CartersDiagnostics

4 ай бұрын

Thank you for watching and commenting!

To stress the spark. Love your videos

@CartersDiagnostics

4 ай бұрын

Thanks bro.

Good stuff

Maybe you could skewl me a bit. So here's what I knew as I watched along. There was no KV spike when you snapped the throttle. That much I knew. I can't decipher much else from ignition scope patterns, but I do know KV should rise with increase in compression. So as an amateur, can you tell me did you have any other way of knowing prior to disassembly that it was secondary and not primary? IE like had you ruled out a weak coil before diving in? I'm thinking about early 3V Fords where the coils were notorious for firing at idle and not firing under load. I do know you said this one was completely dead miss all the time so not quite the same as my example, but do you understand what I'm asking when I say how did you know it was not a weak coil and would be a secondary problem from the waveform?

Nice job , thanks for sharing. Where are you located?

@CartersDiagnostics

4 ай бұрын

👍💯 Virginia

Hi, I am still learning 2ndry ignition, so i paused at around 4-5 minute mark and tried to figure out what is wrong with this vehicle. From the captures i see the coil firing, there is a spark of some sort, there is no turbulence on the firing line, and the kv stays the same. I am thinking either the spark is escaping through the coil boot to the cylinder head or there is carbon tracking on the plug. EDIT: after finishing the video it was carbon tracking on the cheap sparkplugs. Q: could you tell from the captures if the coil boot would be pin holed? What would be the difference? I know its semantics, because the result would be the same and the intake would have to come of anyway. Thank you.

@CartersDiagnostics

4 ай бұрын

Great question 👍Thanks for playing along. From my experience a carbon track just has a distinctive look . They are usually jagged and slope directly down. Its like using electricity to etch live edge wood. The track offers some resistance and seems to burn slower vs a spark jumping threw air to the head. Thats not a scientific answer but thats just my experience. Either way we figured it was ignition and not firing in the cylinder !

@mrblonde2013

4 ай бұрын

Thank you for clarifying that, another item to add to my list of experiments/scope practice next time. ​@@CartersDiagnostics

What happened to the candle, was it broken? If there is an electronic throttle, does the engine controller also open it immediately when we press the gas pedal while stationary? Thank you for the video.

@CartersDiagnostics

4 ай бұрын

If by candle you mean spark plug iys a big carbon track, and its possible it was cracked during installation. I'm thinking a slight delay from gas pedal to throttle opening, I've never actually measured the delay.

@ebolti22

4 ай бұрын

@@CartersDiagnostics Why is there no turbulence on the combustion line on a bad plug, but on a good one there is, what does it depend on?

@tedgtfan

4 ай бұрын

@@ebolti22 The spark line would show turbulence because the in-rush of air would blow the spark around showing it as squiggly line on scope, like the flame of a candle if lightly blown on it flickers and jumps around. Mac Vanderburg did a vid where he showed a plug being held outside and blowing air across it as it sparked to show how and what the turbulence looks like on a scope. Since the spark or most was out side the cylinder in this case there would have been little or no spark across gap to be blown around and possibly not as visible on scope. Just my thoughts though.

@CartersDiagnostics

4 ай бұрын

Nice answer to his question 👍. Its actually Mac VandenBrink . I just wanted to get the spelling correct just in case others want to look him up and study his work.

Nice video. Here trivia for you, why does the dwell period on secondary go negative voltage?

@CartersDiagnostics

2 ай бұрын

Whenever I use an inductive wand for secondary, I personally don't trust the numbers I look at the picture its drawing me. But the negative portion of the ringing is the Polarity changes produced from the charging and dis charging of the step up transformer.

@rodvan-zeller6360

2 ай бұрын

@@CartersDiagnostics Thank you for the reply

Enjoy your weekend, Carter's Diagnostics Brilliant video tutorial 👏 👌 👍 SHREWD Carter's Diagnostics From Nick Ayivor from London England UK 🇬🇧 ⏰️ 06:38AM Good Morning 🙏

@nickayivor8432

4 ай бұрын

Can't wait for the next video

@CartersDiagnostics

4 ай бұрын

Hopefully I can make another soon!

Your KV scale is completely wrong, it should be peaking at 30 KV or more. It's to do with the way you're measuring it.

@CartersDiagnostics

3 ай бұрын

I'm sure the KV is pretty high, im using an inductive secondary wand and its in a tough spot, so the actual kv numbers aren't relevant , im more concerned about the change in KV as the demand for it increased and decreased.