1jz cutting out at wot

300zxpwns

New Member
Feb 1, 2009
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well i fixed alot of the problem today. still not sure on exactly the cause.

rewired my safc and made sure all connections were good. the wastegate to turbo vacuum hose on one of the turbos i realized was smaller than the one i had on it before, so i changed that to a bigger hose. after i did that it still cut out some but not near as bad. I change the settings on safc on high throttle to -2 % and it only cut out one time at 5500 and then i added 4% and no problems. Still not sure of the cause.
 

suprahero

naughty by nature
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Aug 26, 2005
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Sounds like you need a tune in a bad way. Have you ever had it tuned by a professional at a dyno?
 

300zxpwns

New Member
Feb 1, 2009
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no i haven't yet. Well while driving to work this morning did a couple pulls and problem is still there, its just not as bad. but still cuts out.
 

300zxpwns

New Member
Feb 1, 2009
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ok here is the first vid with safc on all stock settings.
View My Video

I did a pull w/ -5% fuel taken out. It did not cut out once.


anything over -5% taken out it cuts out bad. I tried +5% and it was even worse. I used to be able to run +10% all the time with no problems.
 

te72

Classifieds Moderator
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Mar 26, 2006
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Sounds kinda like what my car's doing now that I've put on a 3" ypipe... get above 4k rpm, turbos spool to 13psi, and it likes to 'pop'. Feels like 7m fuel cut, but nowhere near as intrusive. You guys sure it isn't fuel cut?
 

300zxpwns

New Member
Feb 1, 2009
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it definately could be now that i can't even run at stock fuel without it cutting out. Have to run it at -5 percent for it not to cut out. I have a walbro in my wrx that i might take out today and put it and see what it does.
 

suprahero

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Do you not see that it was running lean? Your wideband showed a best of about 12.6 I think. For me that's way too lean. If you keep running it like this I see a big kaboom in your near future. Can't you go to the rpm it starts running lean in and add fuel to that rpm and then go to the next and add fuel there? You don't have to do an across the board change like you keep saying you're doing. You really need to get this to a tuner before you're forced to hitch a ride with your friends. Did you ever get Ben to look at it?
 

suprahero

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I watched the video again and it seems it's not as lean as I first thought.


Maybe after tomorrows tuning session with my wife's I can shed more light on the subject. It's been about three years since I've messed with the AFCII. Maybe I can learn something tomorrow that might help you out.
 

sc4me

New Member
Jul 18, 2009
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miami
Hi guys, i just saw the vid, and that sounds alot like what my car is doing.On some runs my afrs are like yours wandering around 12.3-12.6, but i have had other runs with the same settings that they hit 11.9-11.8 . the only thing ive noticed as weird is that when looking at the datalog feature on the emu my injector input/output actually gets values of 0 somepoints above 5krpm. if anyone else has had this problem with the datalog, can you please let us know what you did to resolve it. thanks, and gl to you also 300
 

300zxpwns

New Member
Feb 1, 2009
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i think i had bad gas or something, filled up today and drove around for a bit and the problem got better and better and slowly went away..

wot with -5% taken out afr's are low 11's to high 10s
 

Bigzavs

86.5 1JZ Single Turbo
Apr 21, 2005
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what stations around here do you go to?

theres certain companies in the arlington/grand prarie area that are to be avoided. my car would run like dog shit on gas from them
 

Bigzavs

86.5 1JZ Single Turbo
Apr 21, 2005
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Arlington, TX
i get gas at only Shell, Exxon/Mobil, or Chevron

theyre usually a little more expensive but worth it on a Supra

now i buy at kroger, since its the only local E85 station
 

T701jz

3M ENGINEER - R.&.D
Jul 23, 2005
657
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Santa Clarita Ca.
I use premium unleaded only. I'm sure the canister will play a factor for the pump to work well. I remove the canister but I'm using a pressure relief valve to make sure I don't KABOOM the tank. Pay close attention when your tank is full and when it's low. You'll feel the difference.
 

te72

Classifieds Moderator
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Mar 26, 2006
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Bigzavs;1521157 said:
now i buy at kroger, since its the only local E85 station

You know, Nebraska's only ONE freaking state over, and there isn't anywhere I can get E85 even if I wanted to anywhere NEAR here. On the plus side I suppose, I can get a decent selection of race fuels from a local petroleum company...