Cold SR20DET...breaking up
 

OK...its cold here (average 15degrees). My car is breaking up under full throttle load...anywhere above 4500rpm....so anyone that lives in a cold climate...have you experienced this too? Is this due to the crap gas they sell us in the winter? It had lost a coilpack and has been replaced (thanks to XAT racing for helping me out)...so that plug could be fouled out but I cannot pull it for a couple days...or it could be cold weather making it lean out...or just plain old bad gas making it misfire under heavy load (low boost):dunno:

i dunno, for like that last month or two, from about 2000-2500 rpms it kinda hesistates i guess, not really that, it feels like its just a flat spot.

i use 93 octane so it should be fine, im assuming it may be the o2 sensor which may also explain why i'm running rich as hell

check your spark plugs, make sure you not running rich. If they are black upgrade to a bigger plug so you can burn more fuel

OK....I will pull the plugs this weekend...


I can ease into the throttle and it seems to be ok...but if I go to WOT...when it gets above 4K (at around 10psi) its breaking up and popping out the exhaust...this problem just started after I lost my coilpack..the coilpack has been replaced...so the possibilities are: bad gas or fouled plug....anything else come to mind?

I would suggest checking your PSI level on your fuel system, possibly replacing your fuel filter, and check the fuse on the fuel pump relay...if all of those things check out, then maybe your MAF is going on the fritz and you should get a new one. I wouldn't think that it would be a plug problem unless you are running 12-14 psi. If they are stock plugs, it could be the problem though...I recommend the Iridiums for the engine if you want to get the most out of your SR.

tightened the gap to .028...and running strong...

10 psi huh? Well, a stock SR20 should put out no more than 7 psi. So if you're pushing more boost you should consider getting your fuel pump changed. Either Walbro, 300ZX TT, or 96' Supra TT. Before you start spending any money, can you tell me if your blow-off valve is re-routed back into the intake? A stock SR20 BOV will leak under boost if you do not re-route it. That's if you are running a stock one still.

my problem is my bov, but i think that since i've been running it open atmosheric i killed my o2 sensor.

I need to get down there and check for sure.

Though i know i have fouled out my plugs, but i've changed those already

I have a fuel pump...a boost controller..a down pipe...gt-spec exhaust, FMIC....Turbo XS BOV...a bunch of stuff. With the boost controller set to 0 I still get ten psi....so its in the waste gate actuator..but I am set up for it so I am not worried..this was a situation of miscommunication...the plugs are gapped tight now...come summertime I will open them up about 4thou....

Thanks for clearing it up. Now that makes more sense.