7 psi misfire

[ted_ex]

Alright here's the problem. I can't boost over about 7 psi without the engine misfiring like crazy. I have replaced the plugs, wires, maf. Nothing (the maf was for another problem). I leak tested the intake to 25psi. Nothing. I hooked it up to an OBDII scanner. It says it's running fine. I checked for arcing in the coils and the plugs. Nada. I checked the spark coming out of the coils. Nope. Compression is fine. Everything seems fine. The engine will redline fine as long as I don't boost over 7. It runs perfect until the boost goes up. Also, the problem randomly went away for a while and I was able to boost to 18psi with no problem. The car is a 95gst with the following (but the problem has happened since stock): big 16turbo, mbc, 2.5 inch turbo back exhaust, intake, hks bov, 255walbro, rewired pump, grounding kit, greddy fmic. I don't have an upgraded fpr or injectors or afc....yet. I'm thinking it could be fuel related because everything else seems fine, but I don't know. Any insight would be greatly appreciated. Also, if anyone has any tips on how to get the f---ing fuel filter off I will be forever greatful.

[EclipseRST]

what did you gap your plugs at?

[ted_ex]

iridium preset gap and the wires are oem

[JoeWagon]

Gap your plugs. 'preset' can be over .060 or at .000 if someone dropped the box.

[ted_ex]

No, I checked the gap before I put them in. They are the third set that's been in. I don't remember the exact gap but they were spec.

[BoostedSpyder]

you are just getting fuel cut. you need bigger injectors and some kind of controller like DSMLink or a SAFC like you said you need.

[ted_ex]

I'm pretty sure it's not fuel cut. I've hit fuel cut before and it feels like the engine just blew. This feels more like one cylinder isn't firing or something. It gets really jerky after aprox seven pounds and kind of chugs. I'm doing a fuel pressure test and some other things on monday and if I find anything out I'll let you know.

[spyderturbo007]

Good luck on the fuel filter....all I can say is I've done 2 of these and I will never do it again. You have to move the battery and the plate. Then, bust your knuckles!!! Just be careful with the feed line under the filter (it's a hard line). Good luck!

[LandoAWD]

Originally Posted by ted_ex

No, I checked the gap before I put them in. They are the third set that's been in. I don't remember the exact gap but they were spec.

In what "spec"?

Drop the iridiums, BTW.

[BoostedSpyder]

go with BPR7ES. best bet. all the newfangled plugs aren't designed with turbo applications in mind, IMHO

[ted_ex]

I might be wrong but I think the evo comes with iridium. Pretty good endorsement if you ask me. Spec is whatever is the factory gap and that's what they were at.

[JoeWagon]

The only difference between boosting and not boosting is cylinder compression. If you have good dry compression, it's very likely that your plugs crap out under pressure. Try NGK BPR7ES plugs gapped to .028''-.032'' Make sure your plug wires have correct resistance, the coil has the correct resistance, etc...

[BoostedSpyder]

and the stock EVO boost pressure is a far cry from the true performance of it's capabilities. great for the endorsement if you ask me.

[ted_ex]

god damn. It was the plugs. I feel stupid. Thanks for everyones help. FK iridium plugs.

[EclipseRST]

dont feel stupid... just remember when someone says something try it, dont be like fuck that i have done it already! everyone is tring to help everyone the best we can so we are not giving you a line of BS...see now arent you glad you switched plugs?