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Discussion Starter #1
So today my tuner and i went out to street tune the car.

PROBLEM IS that we cant really tune the car the way we want.

When the car is boosting the afr is right on where we want it to be.

At idle,and when cruising we try to fix and stabilize tha afr we do it right and then out of the blue car leans out to 17+afr at idle and when cruising and gets back to normal only when i push the gas and starts boosting...
Suddenly goes back to normal with 14.5afr at idle and 14.7-15afr when cruising.

Weird thing is that happens suddenly and we cant figure out whats wrong.

Fuel pump??? Maybe...but the fuel pressure gauge shows pressure except when at idle with 17+afr the engine struggles to keep running so you can see the fuel pressure changin a little bit.

setup is d16y8,gt3071r,id 725 injectors,3 bar map omni power,walbro fuel pump,bisi 2.4 with full valvetrain,p30 ecu with crome...

Tried many different versions of crome and nothing worked out.It does the same thing with or without the emulator.

Really we dont know...

Please any idea would be thankfull BIG TIME!!!

The tuner is a friend of mine and well known here in greece,and he tuned more hondas that i even can imagine...and this is the first time that this thing is happening.
 

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Fuel pump??? Maybe...but the fuel pressure gauge shows pressure except when at idle with 17+afr the engine struggles to keep running so you can see the fuel pressure changin a little bit.
So when your at idle you have no fuel pressure? is your Fuel pressure regulator adjustable, or stock? Is it bad?

what is your fuel pressure?

what wideband are you running, and where is it located? What kind of exhaust are you running?
 

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Discussion Starter #3
when at idle shows 50psi fuel pressure.

Stock fuel pressure regulator.Dunno if its bad or not.it leans out very fast and that fast it goes back to normal.
aem wideband.the wideband is ok because its mine,plus we have another one on the exhaust.so two different gauges...car leans out,thats for sure.

im running 3" full exhaust!!!
 

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Is the fuel pressure 50psi with or without the vacuum hose on it??
 

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FPR shouldn't be 50psi @ idle. 50psi should be your static pressure: pressure when there's 0 vacuum (the vacuum line pulled off). When you're idling or cruising (i.e. in vacuum), the pressure will drop down to somewhere around 35-40psi (someone check my numbers, I don't know the exact numbers). If it stays @ 50psi @ idle, then it should definitely not be running lean (it'd be richer actually). Check your fuel filter and your return line for any clogs.
 

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Discussion Starter #8
FPR is stock.

I have mounted a Fuel pressure gauge on the fuel filter and it shows 50psi at idle.the fuel pump is a 300lph walbro...

For sure though that is not the problem PiKapp504 because the fuel pressure its like that since i have the car.weird is that the car started doing this thing now and it goes lean out of the blue!!!
 

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Does the pressure go up as you boost? It's a 1:1 regulator so for every pound of boost, the fuel pressure should go up 1psi. So if you're at 50psi static, boost 5psi, then your fuel pressure at 5psi of boost should be 55psi. Something's not right if you're at 50psi @ idle...
 

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Discussion Starter #10 (Edited)
So i have an update.

Today i started the car,and run perfect for about 2-3 miles.Then it started doing the same thing.
So i drove to my mechanic.

We checked all of the above:
fuel pump and voltage on the pump(14.05)
fpr
different ecu
yada yada yada

So it keeps doing the same thing,so now we think that is something electrical because you can see the voltage going up and down from 10.00v to 14.00v...something is wrong.

Any ideas?
 

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swap out the ELD then, most of the time you'll get a check engine light with it, but never know. I would check all grounds.
 

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Discussion Starter #17
Yeah the wideband is good...plus i had my tuners wideband attached at the back of the exhaust and both where showing the same afr...so it works 1000%.

I will check the o2 sensor because i just installed the exhaust last week with a friend of mine so it could be the sensor...i will check it just to be sure!!!
 

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Discussion Starter #19
is o2 turned off or just off in boost?
this time we turned the o2 sensor off because when we turned it on it was going rich all the way for some weird reason.

By the way the o2 sensor is brand new.

Dunno man something is really fucked up!!!
 
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