aem v1 tuning questions...

gsxr141

Active Member
Oct 24, 2010
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i'm going to record the fuel gauge today and see what it's doing. do you guys really think that i'm out flowing the 255? i was under the impression that they were good for over 500 wheel.
could my 60-1 be flowing so much air under boost that i need a bigger pump?
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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A walbro and 550 should be plenty to max out that turbo.

Either your running out of fuel or your tune is bad.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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rochester
well, i took it out for a drive just now. it's great at part throttle. as i floor it the gauge goes lean then rich as hell. it's weird.
i put in the newer pump, new clamps, and pushed in the little tab on top of the pump. i'm going to have my tuner drive with me and see what the computer says.
as far as the tune goes...... he's very knowledgeable with this system. as i stated earlier, we're at like 32% duty cycle at 3,000 rpm, and by 5,000 we're almost maxed out ..... with no extra fuel.
 

gsxr141

Active Member
Oct 24, 2010
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rochester
Funkycheeze;2022274 said:
I'm very close to maxing out my walbro 255 with only 450 wheel.

we thought we might need a bigger pump and/or injectors.
the problem is..... we're not losing fuel pressure and, the car goes lean whether we're at 11 psi (waste gate), or 15+ pounds.
 

Flateric

New Member
Mar 26, 2008
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Have you checked to see how crispy your connector and plugs are around the cps area. Back when I ran a 7m I had this and it took literally months for me to resolve it. I had everything from slight to bad breakup (happened most at 2500 rpm where the cps plugs vibrated just right and became flakey) all the way to simply having the car outright die when I was cruising at school zone speeds (and then not start till things had cooled down and the connections became good again)

Also you may have a weak or starting to fail wideband. Just went through this with my 2j. It started acting weird, slow response, outright incorrect readings and a drift towards lean after going and indicated extremely rich. The AEM references the O2 for alot of things depending on how the tune is set, mine refused to even start towards the end due to a O2 fault error before startup.

I would check ALL critical plugs and wires, these cars are getting old(ish) the wiring is really outright brittle and bad in places, it's to be expected.
 

need new tires

rubber slinger
Nov 10, 2005
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Dayton,Ohio
Funkycheeze;2021820 said:
Still sounds like a fuel pressure problem. You need to get it on a dyno and watch the pressure on the FPR gauge to see if it stays steady once the engine gets to max boost, or if it drops off as the RPMS increase.


This is a very good post, I have had multiple cars that have this same issue. Most of the time it ends up being a leak in tank from the pump to the hanger. Watch/ log fuel pressure. Idle pressure means nothing in this case, its what its doing when under a load.
 

gsxr141

Active Member
Oct 24, 2010
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rochester
sooooo. i found out what the problem was, after i tried everything else..
apparently the hi-z injectors i bought were actually low-z. wtf?!?!?!?
the strange thing is, my car ran fine when i had them and the lex afm and NO resistor.
at least now i have a fuel system that should be good for 700+ hp. :)