Thanks guys, I gapped them at 0.026 before I had any replies seemed to run a little bit better, will try a tighter gap this weekend when I get time and see how that goes. Thanks.

 

evo 8 factory plug gap is 0.31, so it is not too big, if you are running more boost, it will be too big, check your grounds, maybe cam sensor ground wire is melted somewhere in the harness, I heard this can cause starting issues.

 

did you ever fix this? a big gap wouldn't give you starting problems, it will however cause spark blowout at high rams when you're in boost with those power levels. but with almost 500 wheel horse, if running factory wastespark coils, i'd recommend running more like 0.21-0.22" of gap. COP non cdi you can run 0.24-0.25" in my opinion. its just trial and error you know.

 

Sorry for the late reply... Fouled the old plugs out that were gapped at 0.26 and just now started messing with it again, switched the plugs for the same ones bpr8es and gapped them at 0.22, also cleaned the maf sensor while I had the time, put it back together, still idling a bit rough and seems to feel rough also inside the car.. "DID NOT TAKE IT DOWN THE ROAD DIDN't TRUST IT as the idle was going from 900ish to 1500ish and didn't have time to mess with it much longer."

Also when revving it up a bit it seems to try and drop down below 1k and bog out.

I was also told by a guy at auto zone that with the evo I needed to be running iridium plugs that were 19.99 a piece, or else they would be fouling all the time.. Can someone shine some light on this issue, thanks for the help.

 

Iridium plugs come from the assembly plant because they last 60K. Other than that, no difference from standard plugs.

 

okay, another thing I would check, have a buddy step on the gas while the car is off, and with a flashlight (with uicp removed) look into the intake manifold and behind the throttle plate, sometimes a dirty throttle plate can cause these fluctuations

 

change the coil packs and see if they are the problem.

 

Will evo 9 coil packs work on evo 8? Sorry im not very mechanically enclined when it comes to the evo.. I ask this question because of these https://www.ebay.com/ulk/itm/172111396692

 

Also car seems to smoke a little, i can even see a little bit of smoke coming from under the hood when i give it gas, and it starts to idle rough then

 

Hooked it up and get 2 codes p0505? Would this cause my problem? Air Idle control valve?

Would this cause the sparkplugs to foul out? When I change the plugs it idles for a few minutes and fouls them out... Car does idle rough also...

 

Anyone?

 

that could be part of the issue. plugs are fouling because of to much fuel. if the idle control is messed up it can cause the computer to dump more fuel to try to keep it running. also check your upstream o2 sensor.