Hard to solve misfire need help please!!!!

[REDspydergst]

Ok so I have a 1996 GSX with built head 18g turbo on e85 with DSMlink. My car is tuned properly and it was running great until one day I did a pull on second gear and it felt as if I was running on 3 cyl while I was on full boost. My car now feel as if my spark plugs are not properly gap. It only misfires while im on full boost it does not misfires while im in low throttle. I pretty much checked everything and I still cant find the source of the misfire. It definetally feels like is a ignition or fuel related problem. Any comments are appreciated.

I have checked and replaced the following parts.
MAF
Coil Pack
Spark plug Wires
Another ECU with the same tune on DSMLINK
checked timing
spark plugs gaped to .22
checked compression 160 across the board
checked for boost leaks (there were none)
3 month old rc 1200cc injecrtors( I checked to see if they were clogged but they all looked fine)
Checked fuel pressure( it was fine at 43psi

The only things that I havent replaced are the fuel pump and the fuel filter. Even if my fuel pump is bad and is causing my misfire problem I still see not knock while on full boost so the only thing I can think of is my fuel filter. Could my fuel filter cause my misfire? I really need help on this one because Im running out of ideas of what could be wrong. THANK YOU.

 

[MY1GDSM]

A log would get you a lot farther then anything... . If not at least an Idea of the AFR's you are seeing boost level timing etc when it's missing... .

Could be dispute what you said here the Base timing off ( if you have a 1g Cas) Could be Running rich real rich... . See my response to your other thread from not long ago http://www.dsmtuners.com/forums/newbie-forum/447604-base-timing-dsmlink.html#post153152463

Without something to go off of besides what you are saying IS good there's not a lot anyone can say. E85 doesn't like to go very rich (on a gas scale wideband) before it will have a hard time firing off an can misfire. As well Not picking up knock on E85 is nothing to judge the state of any tune off of... .

 

[REDspydergst]

Thanks for the reply. As for the log I already ran a log of my car and everything seems normal. airflow, everything seems the same even my afrs 11.1. As for my base timing im still running the stock cam sensor and since my car is a 96 and it cant be adjusted the only way I checked timing was whit the timing marks on the oil pump and the cam gears.

 

[Calan]

Sounds like typical spark blowout. Try gapping your plugs down to .019 and see if it goes away.

 

[MY1GDSM]

Thanks for the reply. As for the log I already ran a log of my car and everything seems normal. airflow, everything seems the same even my afrs 11.1.

Still you looking at it an telling and other people looking for themselves is a different story. I understand not posting one if someone tuned the car for you. And would rather you didn't... .

But, regardless 11:1 is a bit rich still On E85 on lower boost levels.

Either way as Calan said try dropping your Plug gap a bit more wouldn't hurt

 

[REDspydergst]

Ok I will regap my plugs to .019 and see what happens. I will also try to post a log tonight. Thanks for help .

 

[boosteddsm98]

to go back to your fuel filter question, it is possible for your car to be starving for fuel bc the fuel filter is clogged. but that doesnt make to much since that it happened all a once and it was running fine. what plugs are you running? and you should not have any problem with spark blowout at .019

 

[REDspydergst]

Ok so I regap my plugs today to .019 and the misfire still occurs. The only thing I did saw during the few runs I did was that the misfire would only occur right when my rpm's hit 5k. I also changed my fuel filter today but it still misfired. Any other things I should check or replace?

 

[MY1GDSM]

Do you by chance have your 2 step, Nlts, Als set at 5k rpm?

 

[REDspydergst]

I have my 2 step antilag set at 5500k rpm with -10degress of timing. Its weird the misfire occurs right when I hit 5k.

 

[REDspydergst]

any other suggestions?? can i bad knock sensor cause a misfire? I was thinking my front o2 sensor going bad but the logs show its working right.

 

[MY1GDSM]

Post a log of it happening...

 

[94awdcoupe]

slight head lift can do this. water gets past head gasket and blows spark out.

 

[REDspydergst]

So last wednesday I took my valve cover off and I found the source of my problem. One of my rocket arms fell out of place. It seemed like it was due to a fail lifter. One of the intake valves was closed all the time and for certain reason it would only misfire at 5k rpm. Anyways Thanks for the Help!!!!!!