Thread: Tried everything for this misfire

Some of you may have seen my thread from a few weeks ago about fixing a misfire. Well here is the update:

Plugs- new
Wires- new
Coilpack- new
Injector- replaced with tested good one
Cleaned every connection I could possibly relate to the issue.
No boost/vacuum leaks

Car is still misfiring when it sees any boost at all, runs great under non-boost conditions though. This Saturday I'm gonna replace the ICM in hopes that it's the issue. Any input?

Did you do a compression check?

Sent from my SM-G920V using Tapatalk

Yes! Knew I was forgetting something, I checked compression and it tested perfect!

Its only cylinder 1 btw

Weird

Sent from my SM-G920V using Tapatalk

Tell me about it lol driving me insane!

How much boost are you running ? Is the car stock?

Sent from my SM-G920V using Tapatalk

what plugs you use?

icm could be bad, or a bad wire some where.

Wires were tested and found good, TR6 plugs that are 300 miles old.

Car isn't stock but the car was driving great before like 3 weeks ago. No new mods were added, 3.5 pulley btw.

I compression tested and checked plugs to make sure I didn't chip piston or have carbon buildup on valves

are you using a real plug socket? time to time the porcelain cracks during install of the plugs if you use a normal socket.

and by wire i mean one from the cars harness, like a injector wire or a wire near the pcm. things can rub through.

Yea I use a plug socket, I try not to be a hack as much as possible haha the only thing I didn't put the multimeter on is the injector lead. I ohmed the injectors themselves but didn't test the leads going to them. It's just so weird that it fires fine under normal conditions but skips in boost. The only other things I can think of is bad ICM or a bad wire giving reduced voltage to the plugs/injectors

you 100% sure the wires are on right? sh it happens lol

what are the plugs gaped at? this start after or before the plug change?

Plugs are at .55 gap, but this problem was actually worse before plug change. Plugs helped a bit, any chance it could be a glitch in the PCM?

Do you mean plug wires? Lol yes I'm 100% sure they are on right hahaha

you can also look around for a rubbed wire, the metal loop at the dog bone that hols the harness, near and to the pcm, injector harness icm harness and the likes.

ive ran those plugs for like 20 miles, went to al 104's gaped to 0.50, car loves them so much better.

Really? See my car likes the TR6 wayyyy more! Next Saturday imma get an ICM from the junkyard and start looking for freyed wires I guess lol

you need to play the gap game with any plug till you feel whats seems best. i gaped em at 60 then 55 then 53 then 50.


nothing felt as good as the 104's gaped to 50, did the same drill with both plugs.


yes thats a lot of plug pulling. and it kinda sucks.


either way, unless the plug is cracked i cant see the brand or temp being the misfire.

I just can't figure it out for the life of me, almost to the point of just buying a new GP lmao

I'm pretty sure I have a extra ICM laying around from when I did my top swap

Sent from my SM-G920V using Tapatalk

did you try throwing the kitchen sink at it? all joking aside i hope you get it fixed