Misssfire. Need suggestions.

While driving back and forth from Ft. Walton last night I developed a misfire. The car had none of my new mods on it at the time so I was stumped.

I got to my friend's house and I noticed that I didn't tighten my o2 sensor enough when I took it out the other day so I just assumed that was making me run super lean. I screwed it back in and thought nothing of it. Soo the 3" turboback, new water pump, radiator, springs, and wide band go in. I take it for a drive to see how it sounds and feels; but it starts to starter under WOT.

Sooo, I was like "lame..." I went and got new spark plugs that Jimmy recommended me, gapped them at 32, checked all my coil packs, anddd drove around for a few minutes... still misfiring. I pull the brand new plugs out to see that they are white.

My wideband is reading in the 16-18 range under WOT so I don't want to go WOT anymore, haha. If I give it 90%ish throttle the a/r's stay in the 15's which is still pretty lean but it pulls hard to red line making 5psi. It's running on waste gate pressure so it's set at 7psi. If I go WOT at all it starts to stutter.

I boost leak checked it only to find that my stupid HKS flange is a SCREW ON flange so it was leaking. I fixed that tiny leak and found no others. I'm hoping that it's bad gas because I filled up after having less than a quarter tank on my way to Ft. Walton. I know it's not likely but I can still hope, hah...

Help please.

i had the same problem with my talon, it actually was some bad gas.

I'm praying for that but I doubt it.

I know this super cold weather isn't helping but the car started doing it out of nowhere. I'm going to run some fuel injector cleaner through the next tank of gas and see if that helps any. Also going to test the TPS and MAF wiring as soon as I have the resources.

what's your fuel pressure at??? you gotta adjustable fpr???

Nope. I guess wheels and LSD aren't next on the mod list...

FPR w/gauge is next, haha. It should be good because I've got a walbro 255lph pump.

does it studder only under a certain condition.. say only at 3000 rpm? if it only happens if certain conditions are met.. check yer vacuum lines.. thats one of the first things we got crammed into our heads in techschool. lol

well you still gotta stock fpr.....so the 255 only making the fuel more effiecient on stock fuel pressure.....definitely need to get a adjustable fpr or get that neo on.....

Are you running stock injectors?

2500rpm is maf problem.

it could be spark, but if it's only happening at WOT then it sounds like a fueling issue. boost is very picky about afr's and if it's 15 and above then i would deffenitel start with the fuel.

Yes, stock injectors. I need to get a multimeter and check my MAF and coil packs.

if you're able to run up to redline i doubt it's the maf. and the coil packs you can check without a meter, but if they're sparking at idle then they're probably good. SOMETIMES a coil will spark at idle but not top end though....but you'd have a rich condition if that was case b/c fuel was not being burned. with it going lean it's probably the fuel system

how often do the little ignitor modules go bad on those?

Apparently they go out pretty often on SR cars. Lame...

Usually it is an all or nothing kind of deal on the ignitors, coils too. I have extra coils/ignitors.

FightersGarage wrote:

Usually it is an all or nothing kind of deal on the ignitors, coils too. I have extra coils/ignitors.

maybe they'll listen to you, cause i wouldn't have a clue what i'm talking about! LOL

haha, Robbie. I already told Will to check fuel pressure.

I swapped out coil packs yesterday at a friend's house and nothing changed...

I don't have a fuel pressure gauge or any way to check it.

I have tester / gauge where in pcola you at? I'm at 29 and ten mile roughly. The tester just screws onto the schrader valve on the fuel rail . You're problem definetly sounds fuel related . You can borrow it if you want.

I live off West Michigan Ave. down the road from the Mobile Hwy intersection in a culdesac away from dem ghetttooo neighborhoods, haha.

Humm, I'll have time tomorrow so give me a call at 525 1941 and lemme know when I can pick it up or just come use it real quick. I appreciate it in advance, man.

I left a message this morning. I'll be in your area in an hour or so give me a call at 393-8483
Craig