1jz running lean in boost

stevenr816

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OneJArpus;1633809 said:
Do you have the stock fuel damper?


12v mod, is it normal to see 12.x? I see 13.x (what ever my alternator is charging at). Shouldn't it be a little higher?

When does the misfire happen? Full throttle? Partial? In boost? Going into boost? Cruise? Low RPM? High RPM? Does it happen in neutral?
We've tried 2 feed lines both the Driftmotion ss feed line and the stock line with dampener. Going to the stock line got rid of our 3k rpm cut. So the stock one is still on there.

Fuel voltage could be a tad higher but I gaurantee .5v isn't going to fix anything at that low of a boost and injector duty.

Misfires only happen in boost as the arts get leaner is when it breaks up which is 16+ afr if reved all the way to redline. But only last the 16afr mark if we add mote boost it gets worse cause it runs even leaner faster. No idle, cruise, partial, full throttle out of boost etc.

I will get a wideband log and post it up, aswell as a pic of the engine bay
/electronics.







---------- Post added at 10:57 PM ---------- Previous post was at 10:56 PM ----------

Does anyone see the black/orange ignition wire to the injeectors hooked up in the wrong order causing a problem? Doesn't to me but the first time we wired the injectors to the resistor box it was something like 12, 34, 56 and wouldn't start. Now we did whatever way a guy on SM said and worked that was months ago. So were taking out the resistor box and wiring it back up complete stock in the same batch order and the tsrm wiring diagram shows.
 

Albert

Custom CT26, CT12a, CT20 upgrades
May 13, 2009
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Okay guys small update:

I put the AFPR back on with the brand new diapram, I set it to 40psi with no vacuum. With vacuum it sits around 30 something. and when I go get into boost it goes up to 40psi but once it hist positive pressure, it immediately drops to 15-20psi, goes lower the longer i pull/further i go into the RPMs

I have:
A brand new 255lph pump
A brand new fuel filter
NO dirt or junk in the tank
DM feed line Is on
injectors were flowed/tested
12v mod

So Can anyone tell me why my Fuel pressure is dying in boost? Ive tried different vacuum lines, and different ports! please HELP!
 

CyFi6

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Oct 11, 2007
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Do you have a new feed line from the tank up? Make sure there's no kinks or anything in any of the lines. I would probably do a fuel pump volume test to rule out the pump, supply lines, etc. If you know the pump can flow the correct volume as tested from the line leading to the rail, you know no lines are restricted and the pump can do its job. If the volume test checks out you know its something after the supply line at least (assuming its not pump voltage under wot causing your problem).
 

stevenr816

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Look at the line coming out of the filter
sm_photo_missing.jpg
 

stevenr816

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mk3tattoos;1636702 said:
glad to see you found the problem, good call CyFi6! lets see a video of that beast in wot now:)

guess thats what happens when you change the fuel filter in the middle of the night?

now its shooting big fire balls/breaking up in boost so need to be tuned with the bigger injectors. atleast we know its getting some food
 

Albert

Custom CT26, CT12a, CT20 upgrades
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gurley0916;1636753 said:
Definitely get some videos up!

As requested. Words speak for Them self :) 17psi still needs some tuning in the top end
http://s23.photobucket.com/albums/b395/stevenr816/Supras/Albert/?action=view&current=be4b53fc.mp4

http://s23.photobucket.com/albums/b395/stevenr816/Supras/Albert/?action=view&current=9fd91124.mp4

http://s23.photobucket.com/albums/b395/stevenr816/Supras/Albert/?action=view&current=77315b79.mp4

sorry about the shity camera. Just an Iphone. I'll try and get some high def vids up.

Me vs my buddy with a talon fully built @ 15psi. With a 20g turbo.
http://s23.photobucket.com/albums/b395/stevenr816/Supras/Albert/?action=view&current=1ed35f85.mp4
 

stevenr816

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Albert;1637929 said:

easy, its a small 16g, i wish a 20g then it would have been a race.
and photobucket compacts the video so im uploading stright from my computer later, iphone4 = hd videos
 

Dylan JZ

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Oct 18, 2007
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Albert;1637929 said:
sorry about the shity camera. Just an Iphone. I'll try and get some high def vids up.

get an iPhone 4G.. they're filming tv shows with it at this point. it's more of a promotional thing, but if they're using it for that purpose, then youtube videos shouldn't be too bad.
 

stevenr816

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Dylan JZ;1638113 said:
get an iPhone 4G.. they're filming tv shows with it at this point. it's more of a promotional thing, but if they're using it for that purpose, then youtube videos shouldn't be too bad.

My post above, it is a iPhone 4 but when I upload straight to the photobucket app it downsizes hardcore