Here is my setup

Walbro intank
RC370cc injectors
V-AFC
B&M Regulator (recently modded thanks to the help of fellow H-T members)

I am running really really rich and cannot lean it out anymore.
Even if i go to -50% on the VAFC my 02 voltage is still over 1.0 sometimes hitting 1.4

I cannot figure out whats going on that i am getting so much fuel

I see people running 440's on the AFC HACK and there only at like -40%
i should be around the range of -20%/-30%

I am now able to lower my fule pressure but even going down at 30psi its still very very rich.

Any help is greatly appericated

Edited ---Question do i need a resitance box for 370's???? can that be my problem
2nd Edit --- I just measure the Ohms on the stock injectors and they are 12.3 and the RC injectors are 17.0 --- Is this my problem if so what can i do>?

[Modified by NeXtLeVeL_TyPe_R, 6:43 PM 6/2/2002]


[Modified by NeXtLeVeL_TyPe_R, 7:12 PM 6/2/2002]

 

To get my car to idle 370s I had to lower my fuel pressure to 28 psi with vaccum and set the vafc to -39%. I had my fuel pressure 2 psi lower but it idled a little lumpy, maybe the fuel spray pattern was crappy, but I raised it and everything is running much better. I'm still running and inline pump with a 6:1 fmu. My friend has a walbro and he couldn't lower his fuel pressure lower than 50psi, so that might be why you are running so rich. Good luck.

and no you don't need the resistor box.


[Modified by turbosol, 5:39 AM 6/3/2002]

 

man! im still confused. i thought having a vafc meant you dont need a fmu anymore. what are the benefits of having both AND a fpr? do i need all that?

 

You dont!!! But there is alot of ways to setup the car to run under boost...alot of ppl use a low FMU + big injectors + afc...its just how you setup your car.

I personally like big injectors and the afc...i dont like using a fmu.

liam

 

The only thing i can think of is...are you use those are 370cc injectors? Maybe they sent u 550s by mistake? You should have your afc set at around -20% -> -30%. I have 450cc DSM injectors and my afc is set at -40% -> -35% and it runs very nice.

Check your injectors!

liam

 

sorry to take over this thread, but i just wanna ask one more question. im deciding between 2 setups for my 99 gsr w/ an fmax kit:

1- VAFC w/ 370cc's and an intank pump

2- 8:1 FMU w/ an inline pump and 310cc's

which is more reliable, and whats better or worse about each?

 

Just a quick stupid question, what does VAFC and AFC stand for. Thanks J

 

vafc- vtech air fuel controller

afc- air fuel controller

 

Thanks dude. Later J

 

80/290 = 27.6% so -27% for stock to 370s(assuming 290cc for stock injectors at 43psi)

however, this is a rough estimate, and how do you know you are running rich? a/f gauge? because even if your in the ballpark, the ecu will adjust itself and quite rapidly as you play around with the afc

 

How did you modify the regulator? Was it to relieve the pressure at idle?

 

On my turbo LS/VTEC setup, I run RC370 injectors (you do NOT need the resistor box), VAFC and Vortec super FMU. My fuel pressure at idle is around 55psi (can't get it lower). I have the VAFC leaned out 22% at 1000rpm, and the car idles fine. The disc inside the FMU is 6:1. I boost 10psi, and the car doesn't break up, or feel "fat" from being too rich.

Maybe your O2 sensor is bad. Do you have an EGT gauge?

 

This is a dumb question but are you trimming both the narrow and wide throttle maps to ~-40%? That's the only reason I can think of for you to be running rich.

Also, I don't know how accurate reading the voltage of the O2 is for WOT operation. The stock narrow band O2 is only accurate around stoich operation.

 

You need a wideband O2 sensor to confirm that you're really running rich. With no FMU, 370s should not deliver enough fuel for you if you're running more than 5 psi or so.

 

I have the same question. Did you drill a bypass hole in the FPR to lower base fuel pressure. If you didn't then that is your problem. Also, even if you get the vacuum-off pressure down to 40 psi, make sure it also goes down with vacuum applied. That is how the FPR works. It lowers pressure with vacuum and increases pressure to the base pressure at 0 pressure.

Randy

 

Sorry i took so long to post back

I modified my FPR thanks to the help of 5 liter Eater he directed me to a website that showed how to drill a pressure relief hole in the FPR.

So that lets me modify the fuel pressure as low as i want but it still doesnt seem to make a difference

I dont know if my 02 is good or not but i know the car is running rich....it smokes at idle, wants to die at idle and backfires and boggs out all over the place... Its definitly running rich

How can i tell if they sent me 550's??

The only difference on the injectors is i measured the ohms on the stock injectors and they where at 12.3 and the RC's are at 17.2
I wqas going to run a resister to get the RC level to what stock is....In my mind i am thinking thats the answer because it seems like the only problem i can see

As far as the VAFC
I lowered the percentage in Wide and Narrow throttle....
Then someone recommended changing the VAFC throttle setting to ** instead of the arrow up... This makes adjustments only in the wide throttle that didnt make any difference

Quick VAFC Question what should my Low High percentages be I know the Stokc VAFC Setup is 10% 50 % --- I saw on a website that they changed it to 98% 99% --- does this make a difference what should i be running

Thanks for the help so far hopefully i will find the culprit soon

 

I called RC today and they said that the impedance being higher does not matter

Sounds wierd but they should know right?

 

There are only 2 posibilities.
1, is they are BIGGER than 370s like liam said,
or 2, something is wrong with your vafc/fpr install.

Are you sure the vafc is installed correctly? Also, what about your fuel pressure gauge? i've heard of faulty gauges before...

I have 450s myself, and at -50% i would be pretty damn lean... i'm leaning towards they are not 370s in there..... Anyone you know have injectors you can swap out to test?

 

i've found a set of 550cc injectors for a good price. would this be overkill or will the afc be able to control the fuel level? if not any idea where i can purchase some dsm injectors? Also, are dsm injectors peak and hold or saturated? what are the differences? thanx