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Discussion Starter #1
Raising fuel pressure resulting in leaner AFR!!!

At

20psi = 14 afr
30psi = 16 afr
40psi = 18 psi.

tried a diffrent AFPR,
remained Same..

changed the Fuel Pump... (from Inline Bosch To walbro)
Remained Same...

what could it be....
 

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NO SOUP 4 U
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Raising fuel pressure resulting in leaner AFR!!!

At

20psi = 14 afr
30psi = 16 afr
40psi = 18 psi.

tried a diffrent AFPR,
remained Same..

changed the Fuel Pump... (from Inline Bosch To walbro)
Remained Same...

what could it be....
First.... you need to give some more information.
What motor? What Mods? Do you have a Standalone or a Piggy back? Standard O2 sensor? Wideband? Hukka?
 

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Discussion Starter #3 (Edited)
First.... you need to give some more information.
What motor? What Mods? Do you have a Standalone or a Piggy back? Standard O2 sensor? Wideband? Hukka?
1jzgte
440cc
safc
FCD
single turbo
fuel cell
Bosch inline.
all piping is 3"
wide band (lm-1), narrow out put connected to ecu..
FMIC
 

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Madd Tyte JDM yo ®
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7,014 Posts
What map sensor are you running?
What are your fuel corrections on the safc?

With Stock fuel press (~28psi static) and 440s on a 1j map sensor, you should be about -15% to keep it from Loading up. That's about how much the 440s will flow vs the stock 370s. all else being the same. Try going back to square one before jacking the fuel pressure. Then, if you're hitting fuel cut, raise the fuel press and dial back the safc. I'm curious to see how the car reacts to that.
 

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Madd Tyte JDM yo ®
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Lol
Wut?
 

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Discussion Starter #7
Sorry,,,,


Not 440s, They are 850cc......
DENSO 850CC(2450)
Same ohms(13.8)
same connector..

SAFC
-45% correction....


I have edited... my mods list, I also have a FCD....
I disconect the O2, if its responding that fast to lean the car in 1 or 2 sec...
but it remained same.....



I took the car for tunning AFR with these injector,
when the car goes in boost, the AFR was lean(high 13's), i am running 1.5bar.....
Even i took the correction to -15%, but AFR was constantly 13.5 aprox...
in the end i tried to increase the fuel pressure., thinking that most aftermarket injector are flow tested at 43psi, at that moment my fuel pressue was set to 25 psi . as i increased the Fuel pressue through AFPR, the AFR started to lean... as i meantioned above,
when i reduce the fuel pressue, the AFR come down to 14's....
 

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Discussion Starter #8
Guys I just installed these injector as if I can use them with safc. That's why I installed them to test if they can be used without an engine management.

I'll be reverting back to 440cc.. I'll keep u guys posted..
 

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Madd Tyte JDM yo ®
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Is you're fuel pressure increasing under boost?

Might be a chance your injectors were labeled wrong?

I'm pretty sure the impedance should be low: 3-4ohm... I wonder if thats affecting anything
 

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Overlooked
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If this is the same as the other thread, just put the stock o2 back in and tap a new hole for the wideband. As far as afr's leaning out with higher boost, that's obvious. Too much boost and not enough fuel. You're also probably out of the efficiency area for your turbo at 40 psi and pumping hot air. The map sensor sees less density at the higher levels and dumps less fuel. You, my friend, are trying to put 5lbs of shit in a 2lbs bucket...
 

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Overlooked
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Also, 850cc injectors will need a fuel pump that can flow 325lph safely. A single walbro can't do that and i believe a bosch can't either.
 

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Discussion Starter #15 (Edited)
Also, 850cc injectors will need a fuel pump that can flow 325lph safely. A single walbro can't do that and i believe a bosch can't either.
cant i use, narrow output from a wideband o2 ??
40 psi is the fuel pressue, not boost!!
rasing fuel pressue at idel is resulting in lean afr..



try a new wideband. .
this is a new wideband...
 

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Overlooked
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He's suggesting that air is getting into the exhaust before the o2 which is a reasonable question.

I still think you need a second fuel pump.
 

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NO SOUP 4 U
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when you change pressure its smart to pull the efi so the ecu can relearn the new pressure. otherwise it just gonna keep acting stupid.
Is that what they do in the Super Secret Supra Club? So.... that explains why you are its only member.
 

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Also, 850cc injectors will need a fuel pump that can flow 325lph safely. A single walbro can't do that and i believe a bosch can't either.
this is a big problem on your car! you need a second pump!
 
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