I'm getting misfiring at 25PSI on stock turbo.

I havn't gotten it before until I put on my test pipe, and I started spiking at 25/26PSI in 3-5 gear.

It won't misfire in 1 and 2nd, (when I'm only running around 23).

I'm pretty sure its because of my spark plugs (still stock IX plugs), and I think I should go one step colder. Basically, I searched, and cannot find what plug (1 step colder) that I should go with. I know that because it is an IX, I can't just use the NGK plugs that Autozone sells. There has to be something cheaper than the $140 stock replacements that Mitsubishi charges.

Any opinions?

Would Denso IKH22's work?

Lastly, what should I set the gapping at?


MOD LIST:
-TBE Exhaust w/ Downpipe
-Walbro Fuel Pump
-BR Intake
-Forced Performance 18lb Wastegate (Set at 24PSI, but seeing spikes of up to 26PSI)
-ECU tune

I made 379whp, 353wtq on a Mustang dyno, which reads like a Dynojet. This was before I installed the Test Pipe, if that makes any difference.

 

IKH 24 - Are one step colder. I picked mine up from sparkplugs.com - they are not listed under the evo specific plugs if you search by car. You have to manually search for them.

 

Gotcha, I think I'm going to order them off Amazon, since I have a $10 Gift Certificate.

What should I gap them at?

These are the same plugs correct?
http://www.amazon.com/Denso-Iridium-...1046862&sr=8-1

 

Might want to take a stroll through this thread...

https://www.evolutionm.net/forums/ev...ead-plugs.html

 

I found this thread out RIGHT after I made this thread.

I even posted in it too...

I ordered the IKH24's, just confused on what I should gap them to? One more stupid question, will going one step colder give me anymore performance gains? Or will it just make it so my car won't misfire....(which would be performance in a way..)

 

No, getting a step colder plugs will not give performance gains.
Check the insulator around the electrode. If it is a yellowish or blistered, then the plugs are too hot. Need to go one step colder.

Going to a step colder plugs when it's not needed can actually make your car run not at its full efficiency.

With bolt on mods, you should be fine with stock heat range.
If you are on stock plugs, that's probably what's causing the misfire. change plugs, and you should be fine.

 

i have been running the stock iridiums on my IX, i have ran them to 30lbs on race fuel 110 and no issues many locals have also done so.

make sure they are gapped correctly,,,,, are you tunned for youre mods and boost levels

 

It's not the insulator that tells you, that only shows additives and deposits in the fuels and whether or not you're getting detonation. Light detonation shows up as black pepper spots on the porcelain, heavy shows up as glittery flakes on it. The ground strap is what shows you the proper heat range, after running a plug you'll notice an off-color mark that appears on the strap. That's the annealing band, and depending on the position of it on the ground strap depends on whether your plug is too hot, too cold, or just right. The proper heat range should show the annealing band right around the curve of the ground strap or slightly below it.

 

I have taken out my plugs and looked at them, and they were all very white. This was leading me to the interpretation that the plugs were lean, thus needing 1 step colder plugs.

I didn't get the misfire until I started spiking at 25/26PSI w/ the test pipe.

And if my stock plugs went out at 18k miles, isn't that sort of a big problem? I didn't think they would go out that fast.

Anyways, I already ordered the Denso IKH24, so hopefully that will work.

 

White porcelain is good, that means that the carbon is burning off during normal driving the way it should. Most people confuse how to read plugs, thinking that it's the entire section of the porcelain that will change to a nice rich brown color when you have a properly tuned fuel map. Actually it's the base of the porcelain in the well of the plug that tells you what your full throttle afr's are. 1 step colder plug at 25/26psi isn't a bad idea at all, and for that range I'd gap them to .024 to keep from blowing the spark.