Misfire Issues

[TwizzleStix]

Hmmmm? Do you have 93 fuel? I do and I'm essentially at sea level and have NEVER had any misfires with MPT 93 or Cobb 93 tunes. I'm even running a bit "more" Load/Torque than the normal Cobb tune. Obviously the coil packs can cause issues, but I would suspect poor fuel quality as the culprit if you're past the coils. Have you tried a good octane booster?

 

[Donovan]

Got it - so coil pack could be causing those misfires at WOT when tuned.

Maybe I'll go ahead and grab that MPT tune now.. since my CEL has been fixed due to a chaffed wire on the o2 sensor.

 

[peavey02]

Update.....

I couldnt find the culprit regardless of which spark plug/ignition coil switch I did. Brand new oem plugs gapped to .028 (triple checked using two gap tools). Still no luck........

I finally broke down and disassembled the ignition coils and boots to remove the spring retainers inside the boot. To my surprise the entire middle portion of the spring was filled with what looked like hardened die-electric grease. I thought this was odd so I took a pipe cleaner and cleaned it out with the help of electric connector spray cleaner.

So far I have made 10 back to back WOT pulls to include two hard launches from a stop all the way out to the limiter and up to 107 mph. I said screw it if its gonna blow might as well be today lmao.....

The truck is pulling hard all the way through each gear and all the way up to 107..... Needless to say the truck is performing as it should and I'm glad to have found what seems to be the culprit to my constant misfire issue. Cant wait for my stg2 hardware to go on next week.

Shout out to @wgr73 to being right there through the whole process again. You rock man.....

Wish I would have saw this yesterday. haha My truck is doing the same thing under WOT. I need to get another laptop so I can get FORSCAN back. I just said screw it and dropped if off at the dealer this morning.

 

[FordTechOne]

Wish I would have saw this yesterday. haha My truck is doing the same thing under WOT. I need to get another laptop so I can get FORSCAN back. I just said screw it and dropped if off at the dealer this morning.

You brought it to the dealer with a tune?

 

[peavey02]

You brought it to the dealer with a tune?

no tune, I've never had one. My truck is misfiring at WOT.

 

[FordTechOne]

no tune, I've never had one. My truck is misfiring at WOT.

OP’s truck is tuned, that’s why I was questioning.

 

[peavey02]

OP’s truck is tuned, that’s why I was questioning.

Understand, I was just looking around for ideas and saw this post. My engine is stock besides the Wagner intercooler. I keep getting a misfire on cylinder one at start up and at WOT. At WOT the check engine light would kick on. I hit 50150 miles and it all went to hell. Haha.