Ok, my car is having the following problem...

ONLY during WOT it really stutters. Kinda like it's misfiring or hitting the fuel cutoff! Like I said it's not a problem with a gradual acceleration, but when you really punch it, like getting onto the freeway, I have to back off on the accelerator until it behaves again. It seems to happen from 5k-red line.

It's actually pretty embarrassing when I was trying to hotrod out of a gas station driveway, punched it, and sputtered across the intersection!

-Maybe my plugs? But, they were changed 10,000 miles ago.

-Vacuum leak? Can't find any lose hoses though.

-Bad gas? But I only use Shell or '76.

-MAF?

-Piggyback?

I don't know! Any ideas? Most of you know my mods, and it only started about 2-3 weeks ago. I wanted to go turbo in the next few months, but not before this is fixed!!!

 

i pity the fool whose car sputters i do, i do!!

 

i don't think its the gas you're using. If you have a CAI check the sensor thats attached to it. When i installed mine i left it loose and the car did the same thing yours did.

 

I had the same thing on my old car. turned out to be an 02 sensor. might help ya. maybe.

 

Just checked this... appears fine.

I just ordered some new NGK's to see if this helps... Maybe there's a prob with my Denso's?

 

You mean the one that's in the downpipe?

 

sounds like a coilpack problem to me. Do you live somewhere really hot???

 

Just had the same problem with mine, 13,000 miles on it and it would barely idle, and forget about driving anywhere. I'm not currently in country, so I had my wife have it towed to the dealership and they had to replace two spark plugs. All covered under roadside assist and warranty. Thanks Mitsu!!

P.S. No check engine light

 

I live in San Diego. It's always 70F here!!!

If plugs don't work, I'm going to remove my piggy-back. If that doesn't work, I'm going to try and swap my MAF with someone and see if that's the prob.

This sux. I'm like $1,000 away from my turbo, and I won't get it until this is resolved.

 

Good luck. It'll probably turn out to be something simple. I doubt it would be the coils or the MAF, you probably would be staring at a check engine light.

 

Your engine is misfiring...is your check engine light on? if so..its most likely your plugs. Keep OEM plugs in or go platinum with the same style as OEM. For a relatively new car...its got to be the spark plugs you replaced. If not, try to see if you mas is connected correctly. Engine misfire and stuttering means you are hitting fuel cut.

 

sounds like a maf. when i worked for mitsu i had the same problem with an eclipse that came in, i found a feather between the honeycombs in the maf, lol. but if it DOES turn out to be a coil let me know i think i have an extra one in my parts bin from when i quit turning a wrench for a living.

 

is it misfiring or starving for air? it could be an air map sensor, maybe you have a leak and its sucking in to much air and keeps closing your throttle.

 

Kinda sounds like something along this line? What should I check for? Does the MAF sense too much air and close the throttle, or is it a different sensor?

 

Since it's the Ralliart, at 5k isn't that when the MIVEC kicks in?