Misfiring while in boost.

[Bignoga]

Hey,

At high boost I'm having an issue were I am misfiring sporadically. I had this issue ever since I removed the boost restrictor, I replaced the plugs with BKR7E-8 and the issue went away. My car is running pretty rich so I have to change plugs ever couple thousand K's. So I started having my breakup issue again two days ago. I pull the plugs they are black and fouled even while running water/meth setup. I change plugs again to BKR7E-8's however my misfiring hasn't gone away. I checked my coils they seem fine is there anything else it can be? Should I try closing the gap a bit more?

Thanks in advance,

Kyle

[GTS-James]

well im not 100% sure but back when i had my gtst i had the same problem with missing while under hard boost, my problem was injectors, than one of em pooped and leaned out cyl.1... aka new motor job. id check your injectors.

[derbeck]

Are you running 91 octane

[nelsonmxmarc]

Why don't you look into your enrichment issue? Is the car tuned, or are you just piggybacking it and swapping plugs to alleviate having it tuned?

Running too rich is just as big an issue as running lean; the only difference is that running rich does damage in the long term, while a lean issue can cause problems right off the bat (high heat, cracked pistons/rings etc).

Rich conditions will cause cylinder wash; in simplest terms, it causes the oil to be washed off the cylinder walls and the friction coefficient raises ten fold. Basically you're wearing rings at an elevated rate. This will most definitely lead to low compression.

If you're having miss-firing, start with plugs/gap/fuel/intake restrictions/coil pack/igniter.
But since you mentioned ON GOING extreme rich conditions where its NECESSARY to change plugs every ~2000 km, i'd do a compression test and keep your fingers crossed..

[derbeck]

What is rich ie 10.0 air fuel at 15 psi and are you sure your mafs are good because with water meth your running over 100 octane or a boost leak

[Bignoga]

When I'm under full load I'm around 11.5 going down to 10.9 right at redline. It doesn't seem overly rich to me. I regapped my plugs today to .6 on BKR7E I don't have a misfire anymore though you can really feel the decrease in power having it this small. They were previously gapped to .75 or so. I'm running them at 15 psi.

[leeaspin]

check your injectors....could be dirty or maybe even done for..
had the same problem with my gtr and new plugs with different size gap worked for me
also check your fuel filter could be getting dirty fuel

[Velders]

I checked my coils they seem fine

How did you check them? What makes you think they are fine?

[DarkCaporaL]

Even if you check your coils with a multimeter, it will only tell you if they are dead or not, which should be obvious without a multimeter if that's the case.

Random missfires can be caused by weakened coils or coils that are on their way out. Just make sure your coils are good (easiest way is to swap them with good known ones for a while).