RealDealBJJ

Ok guys, so I swapped cyl 1 & 3's spark plugs and hooked everything back up. I drove the car for a few minutes, the CEL has not come back on and it seems there are no issues....I'm not sure if I should be excited or confused at this point because the other day I cleared the code and the next time I started it up the CEL came right back on. I didn't use a new spark plug, I only swapped them so you would think either the same Cylinder 1 misfire would occur or it would switch to cylinder 3.

I guess we will just see what happens

RockyMtn96XJ

Let us know!!

RealDealBJJ

Ok guys so here is how everything turned out.

I took the coil pack off to replace the spark plug. The first thing I noticed is that the black plastic sleeve from the spark plug socket tool somehow has been on the cylinder 2 plug this whole time(Approximately a year), somehow I didn't notice this stuck on there when I replaced them. It doesn't seem to have caused any issues. lol

Next, the store only had champion plugs, but I had NGK's in the jeep and so I decided to just swap the cylinder 1 plug to cylinder 3. Once I completed that, everything seemed to be running fine. I knew I needed to drive the car a bit to cycle the codes and see the CEL pop back on, so i drove it a bit for a few days.

My wife ad I decided to head back to Cali & made the whole trip with no issues at all.


I'm a bit confused though. If it was the spark plug, then cylinder 3 should have been misfiring, right?

And if it wasn't the spark plug, I should have been getting the same misfire on cylinder 1 & the same vacuum leak, right?

It seems very odd that what I did would completely fix the issue, right?

Can anyone add any input? Should I just be happy and move on or is there anything I should be concerned with?

Thanks for the help

Spencer_P

I would go ahead and order a set of plugs so if and when it happens again you can rule out plugs and not waste your time changing plugs in a parking lot. Just my .02

RealDealBJJ

Sounds like a good plan......other than that, is there anything else you think I should check out? or just let it ride?

Spencer_P

I'd just drive it and see what happens. A scanner is a great tool to keep an eye on things while you're driving and can help a lot with troubleshooting. I use my Bluedriver whenever I wanna keep an eye on things, but they make much cheaper Bluetooth scanners as well.

RockyMtn96XJ

https://bafxpro.com/products/obdreader

I use this one. Works great and its your choice on which app you use to read the info. I use the TorquePro app.

Ole' Christian

There are a couple of reasons it didn't necessarily follow the misfire to cylinder #3. The high voltage of an ignition spark can follow many different paths. For instance, if there is a small crease in the boot, or the boot is slightly cracked, the spark will follow those cracks and potentially misfire, but it would be intermittent. Getting in there, removing the coil, and just moving things around, could potentially "fix" it and you wouldn't even know. Also, misfires, don't have to be just related to plugs, coils, cylinders, or injectors. Sometimes, it's just the terminal tightness in a connector, or moisture that has gotten into the connector. I usually cover my bases when I'm replacing plugs by putting in some di-electric grease in the boot and in the connector as i'm putting it back together. Just some input.

----------------------------------------
Retired ASE Certified Master Technician.................Now Software Developer Nerd 🤓

dave1123

There's also the spring inside the boot that may have not been making good contact with the plug.

Knucklebuster

News Flash!

Solved my intermittent misfire3, misfire 4, multiple misfire CEL with sometimes flashing CEL. Spark plug on cylinder 4 had a chunk of melted plastic booger at the bottom under metal gasket. The plug wad properly torqued to the booger but the metal gasket wasn't seated. Gas was escaping around the threads and the plug was dirty compared to the others. This is serious. Could have blown the plug out, stripped the threads in the head and punched a hole in the hood. My bad. Lazy at last plug change. Next time I'll look down each hole with a light and get my finger in there to wipe everything clean. Two weeks now and no more check engine light!

cruiser54

And all this time we thought you were a world-class booger flicker!

Thanks for the update.

Knucklebuster

Apparently just a piker. What finger to clean out the spark plug hole?

Knucklebuster

Oops

Knucklebuster

You might have had a carbon track on the plastic sleeve, making a path to ground for the spark, especially in humid conditions.