Check my plugs

[Torinate]

Finally able to start to figure out my idle misfires and off idle hesitation.
First up is another compression test. I’ll post the results later.
Here’s my plugs though. Anything look suspect? New plugs 500 miles ago.
Thanks!!

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[Proshop]

1 & 8 don’t seem to be discolored as the rest of them (as far as I can tell from the pic).

 

[Torinate]

Thanks. Yea I noticed that as well. A little more white.
Gap is consistent at what I put them in at. 28

Just looked. #1 was the most consistent misfire and highest number of them in mode 6. All cylinders had misfires at different times. It’s the plug that’s also the lightest in colour.

Plugs have about 500 miles with no hard pulls on them.

Got the compression test done. Different tester than last time. They range from a low of 208 to a high of 216. I think the 208 was actually a fluke maybe as when I started to unscrew it it was completely tight. Likely moved a little when I set it down. But compression is super consistent. Maybe lower than last time overall but different gauge. Car has not ran in 5 months so it’s completely cold with no oil pressure anywhere. Wasn’t look for absolute numbers, just consistency across the cylinders.

Wonder what’s up with #1?

guess it’s time to pull the $&=*> injectors on this. The absolute worst job on an Edelbrock!

 

[Kidroc2133]

Swap plug #1 to a different cylinder and see if it follows before snatching out the injectors. Had a plug that would cause a misfire after driving the car for a while and they where all new plugs. It would go away once the car was cold on first start but came back after driving so many miles again. Bought a new one and it fixed my problem. Also, you have misfire on all cylinders since it sat for those 5 months? No problem before?

 

[Torinate]

No no. This has been going on for 2 years. Idle misfires after it warms up. Nothing during warm up. Only at idle. I have another thread about what’s happening. Idle misfires and off idle hesitation is the name of that thread.

Plugs were changed as a “fix” with no success. Moved coils around. No change. Cleaned MAF, changed TB, cleaned injectors x 3 on the car, smoke tested x 2. Did a compression test last year as well.

Been a frustrating thing!

 

[Kidroc2133]

Oh ok, my misunderstanding and I'm sure it has been very frustrating. Good luck and hope you have it figured out sooner than later.

No no. This has been going on for 2 years. Idle misfires after it warms up. Nothing during warm up. Only at idle. I have another thread about what’s happening. Idle misfires and off idle hesitation is the name of that thread.

Plugs were changed as a “fix” with no success. Moved coils around. No change. Cleaned MAF, changed TB, cleaned injectors x 3 on the car, smoke tested x 2. Did a compression test last year as well.

Been a frustrating thing!

 

[NGOT8R]

They all look good to me.

https://ngksparkplugs.com/en/resour...eral, a light tan,engine is in good condition.

 

[Torinate]

They all look good to me.

https://ngksparkplugs.com/en/resources/read-spark-plug#:~:text=In general, a light tan,engine is in good condition.

Thanks.

Yea, had a look these ones and my old plugs and actually they all look great.
I gotta get this thing figured out so I can make a few track rentals!

 

[NGOT8R]

Have you tried a crank relearn? I had multiple cylinder misfires on my 2019 Bullitt after a clutch install and a crank relearn fixed the issue.

 

[Torinate]

Have you tried a crank relearn? I had multiple cylinder misfires on my 2019 Bullitt after a clutch install and a crank relearn fixed the issue.

Yea. I’ve done multiple crank relearns. Both with Forscan and also nGauge. I’ve done multiple KAM tests as well. No CEL but I can hear it pop at idle and watch forscan mode 6 data record the misfire. The off idle hesitation is terrible. Sporadic. Step on the gas and it hesitates before going. Sometimes it goes. Sometimes nothing then goes.

 

[NGOT8R]

Yea. I’ve done multiple crank relearns. Both with Forscan and also nGauge. I’ve done multiple KAM tests as well. No CEL but I can hear it pop at idle and watch forscan mode 6 data record the misfire. The off idle hesitation is terrible. Sporadic. Step on the gas and it hesitates before going. Sometimes it goes. Sometimes nothing then goes.

What about the MAF sensor. Have you cleaned it with MAF sensor cleaner?

 

[Torinate]

Yea. Cleaned the MAF twice with the proper MAF spray. Green filter, dry.
Keep the ideas coming though! I’m sure Ive missed something. Murphy’s law says that’s what it will be.

 

[Dave2013M3]

Move the coil from the misfire cylinders and see if it moves with them. It could be a coil. Sometimes the misfire isn't enough to kick a code.

 

[Torinate]

I moved the coils around last time as well. It didn’t change anything. I think you’re right. Misfiring enough to register but not a high enough percentage to trip a CEL. The misfires are most prevalent in cylinder 1 but all of them are registering misfires. I put the plugs back in and actually moved all of the coils this time as well. Basically switched them side to side.
I think maybe I’ll do another smoke test but that’s not likely the culprit. I spent an hour checking every connection and wire that I could get to on the wiring harness hoping to maybe find a chafed wire but nothing. I didn’t remove any of the factory tape to look under it though. Grounds are tight. I’m missing something.

 

[HKusp]

This sounds crazy frustrating. I would look at a new wiring harness.

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