1jz goin lean at 6k

[dslocal]

if the gap were too much you'd have spark blowout and should see a rich condition.

Think about it though... If he is having spark blowout combustion isn't being completed right... Now think about this if you don't burn all the fuel and OXYGEN in the exhaust then the OXYGEN sensor would read all the left over o2 in the exhaust right? Showing on the wideband a lean condition. :sarcasm:

That was the way I viewed that.
.028 sounds like a small enough gap but you might try degapping them down to .025 or something, it doesn't take long to pull plugs, and then you can read them anyways

 

[tsupra]

hmm, could be you are correct. but if that were happening i'd expect some backfires to happen when that unburnt fuel together with enough O2 hit the cat and ignitied from the hot honeycomb.

 

[ahmed]

i have full 3in exhaust no cat

 

[dslocal]

still even if you have a 3" your downpipe will be really hot at 6k under boost, probably hot enough to ignite it like tsupra said.
I would pull the plugs and look at them, try to tell if they look like they have soot on them or if they are white from being lean. (probably won't be able to tell though because it only happens at 6k

 

[ahmed]

someone told me it might be one of the coils arcing at high rpm. it started snowing again here in cleveland. but once it clears up ill check plugs and use coils from my buddys 95 tt supra.

 

[ahmed]

ok today i swapped out coils plugs and ignition box from my buddies 2jz. and car still does it.

can it be fuel cut. with race gas i never felt the wall feelin but it still went lean. without race gas i feel the wall feeling in some gears and if i dont feel it it still does lean.

 

[dslocal]

yeah, I mean the only other thing it really could be would be boost cut if you aren't getting spark cutout, and your pump is obvousily good, You never mentioned what psi your running.
Have you tried turning it down and seeing if you still get the same thing?

 

[ahmed]

its at 15-16 psi. i dont even have a boost controller or anything. all i did was hook up gauge and noticed it was 15-16 psi. it gets there fast and holds steady doesnt spike or drop. is there a fuel cut defender mod i can do.

will this work for 1jz
http://mkiv.com/techarticles/ffcd/freefcd.htm

 

[ahmed]

is there a mod to block my map sensor so i can see if its fuel cut or not.

 

[dslocal]

well you can just unplug your map sensor,
The right way to fix this would be a piggyback, I am pretty sure too that stock boost is around 11-12 psi on a 1jz so it sounds like something is going on there. Maybe check the lines from the compressor housings to the wastegates?(make sure there there and aren't tampered with)

 

[ahmed]

when car is cold i can unplug it and it will run but not that smooth but not that bad.
when car is warm if i unplug it or block off the vacuum to it car will not run it dies instantly.