Getting fuel cut, help please!

[Abe'sGST]

Ok, so I got my gst 2 months ago and it came with a few mods. Every time I give it some gas at about 4500 rpm's i get fuel cut, and it smells straight up like gas, so i'm sure its running rich. It has an apexi SAFC and in settings its set on 0 on both low and high throttle. I want to fix this and what i would like is to remove the SAFC but i talked to the previous owner and he said it wouldn't run right if i did that. Is that true? If it is what would be the best settings for it? help please!

 

[LiquidX]

If it has larger injectors than stock (450cc) you need a tune. If you have stock injectors then you can remove it. If it's causing problems then there are issues elsewhere.

 

[Abe'sGST]

That's where the problem is, i have no idea if they are stock or not. If the SAFC is set zero all the way and it's running rich, does that mean the injectors aren't stock? Would a non-stock fuel pump and stock injectors cause it to run rich as well? thanks for the help man

 

[jason91dsm]

list me all of the mods and i can give you a good base tune for the apexi controller

2G Turbo

16G Turbo, RSR Cat Back, RSR DP-no cat, Filter, 17psi, Front Mount I/C, Denso in tank pump, 550cc Injectors, Side and Lower honeycombs out, Adjusting screw backed out flush

Low Setting:
1K +39 2K +13 3K + 6 4K +3 5K +3 5.5K + 3 6K +3 7K +3

High Setting:
1K -10 2K -10 3K -10 4K -10 5K -3 5.5K +6 6K +8 7K +8

TH-Point
Lo 30% Hi 80%



2G Turbo

Big 16 G Turbo, Apex Cat Back, RRE DP-3" Cat, Filter, 19psi, Front Mount I/C, Walbro 255 HP in tank pump, 550cc Injectors, honeycombs all in, Adjusting screw left alone, Big GReddy FMIC

Low Setting:
1K +-2 2K -4 3K -6 4K -10 5K -10 5.5K -10 6K -10 7K -10

High Setting:
1K -21 2K -23 3K -24 4K -23 5K -22 5.5K -22 6K -21 7K -18

TH-Point
Lo 30% Hi 80%


2G Turbo Stock

T-25 turbo, RSR Cat Back, RSR DP-no cat, Filter, 14psi
Stock Injectors, Side and Lower honeycombs out, Adjusting screw backed out flush

Low Setting:
1K +50 2K +18 3K +10 4K +8 5K +6 5.5K + 6 6K +6 7K +6

High Setting:
1K +0 2K -1 3K -1 4K 0 5K 0 5.5K +3 6K +4 7K +5

TH-Point
Lo 20% Hi 60%

just remember these are just base tunes you will have to fine tune

 

[BurrowZ]

list me all of the mods and i can give you a good base tune for the apexi controller

2G Turbo

16G Turbo, RSR Cat Back, RSR DP-no cat, Filter, 17psi, Front Mount I/C, Denso in tank pump, 550cc Injectors, Side and Lower honeycombs out, Adjusting screw backed out flush

Low Setting:
1K +39 2K +13 3K + 6 4K +3 5K +3 5.5K + 3 6K +3 7K +3

High Setting:
1K -10 2K -10 3K -10 4K -10 5K -3 5.5K +6 6K +8 7K +8

TH-Point
Lo 30% Hi 80%



2G Turbo

Big 16 G Turbo, Apex Cat Back, RRE DP-3" Cat, Filter, 19psi, Front Mount I/C, Walbro 255 HP in tank pump, 550cc Injectors, honeycombs all in, Adjusting screw left alone, Big GReddy FMIC

Low Setting:
1K +-2 2K -4 3K -6 4K -10 5K -10 5.5K -10 6K -10 7K -10

High Setting:
1K -21 2K -23 3K -24 4K -23 5K -22 5.5K -22 6K -21 7K -18

TH-Point
Lo 30% Hi 80%


2G Turbo Stock

T-25 turbo, RSR Cat Back, RSR DP-no cat, Filter, 14psi
Stock Injectors, Side and Lower honeycombs out, Adjusting screw backed out flush

Low Setting:
1K +50 2K +18 3K +10 4K +8 5K +6 5.5K + 6 6K +6 7K +6

High Setting:
1K +0 2K -1 3K -1 4K 0 5K 0 5.5K +3 6K +4 7K +5

TH-Point
Lo 20% Hi 60%

just remember these are just base tunes you will have to fine tune

No offense but those don't really look.. right. +50% at 1K with exhaust, intake, stock injectors and the BISS screw backed out nearly fully? That's pigggggg rich at idle.

I personally would not tune it with the SAFC unless you are running at least a wideband (with logger preferably but not required). If it has stock injectors you shouldn't have to adjust anything. It essentially is just a monitor for TPS, RPM etc.

 

[jason91dsm]

RRE's Super AFC Setting and Adjustment Tips

 

[BurrowZ]

RRE's Super AFC Setting and Adjustment Tips

Okay I see. That's strange to me I'm going to have to read up some more.

EDIT: Durrr.. no honeycombs. I get it now.

 

[Abe'sGST]

ok, of what i know i have is just a front mount i/c, safc, aftermarket blow off valve, and apexi turbo timer...i believe i have the stock fuel pump, and i have no idea about injectors

 

[sugarfree]

best thing to do would be get a wideband and then start tuning from there. Also install a boost gauge/verify yours is working properly because if you're overboosting due to a faulty boost controller or something along those lines it's going to fuel cut. check your wastegate source to make sure it's not disconnected because i don't believe our wastegates have springs like an external. The wideband will help immensely in giving you an idea of whats going on and allowing you to tune it to run better.

 

[bryanwheat]

If you are on stock injectors i would take the safc out, re attach wires like they were from the factory and go from there. Than do a boost leak test and see what's going on.

 

[Abe'sGST]

yea if i knew that i had stock injectors i would but idk how to tell? also i do have this one vacuum hose with a metal thing in the end and it goes no where, tomorrow imma take a pic an post it, hopefully yall will know what it is b/c i dont, thanks for the help guys

 

[jed344]

If you look at injectors it should be easy to tell if they are stock or not. And if they are just remove the safc sell it and you will be halfway to ecm link

 

[bryanwheat]

Take a pic of the injector. It should be a metal body with a black plastic top on it.

 

[Abe'sGST]

ok so i took these 2 pictures, idk what it is or what its supposed to hook up to, if it can be causing my fuel cut problem?

 

[dsmjunk]

That hose goes to your bov. There shouldnt be a tee there. I think its a mbc but i might be wrong so You might want to ask the p.o what it goes to.

 

[Black'95]

That's a boost controller, bro. The other nipple should go to your wastegate. That's a vacuum leak without being hooked up! And you'll definitely need at least a boost gauge and a wideband to tune that AFC. Honestly, if your entire fuel system is stock, and your turbo is stock (or like a 14b or 16g or something) you're probably ok without the AFC.

And yes, most guys advise against teeing into the BOV vacuum source. Try teeing into the fuel pressure solenoid.

 

[rubadubdub]

I had the same problems you are having. What I did to resolve the problem was to buy an AFPR and adjust the fuel pressure up so the load of the injectors would increase. I just recently bought some 750cc injectors and this completely cleared up my problem. Hope this helps!

 

[bryanwheat]

That mbc being open like that will cause the car to fuel cut because it is causing a big boost leak, along with the fact that the bov will not be held shut because of the leak. Get a new piece of hose and go from the the intake manifold where the old one is hooked directly to the bov. Now you need to check and see if the stock boost controler is in place, or the wastegate atleast has the line going to the nipple on the turbo. IF not than you are also hitting the highest amount of flow that the turbo can do, along with a boost leak, and leaky bov. This will make the car run horrible.

 

[Calan]

What I did to resolve the problem was to buy an AFPR and adjust the fuel pressure up so the load of the injectors would increase.

The load on the injectors (and IDC's) will actually decrease as pressure goes up, but the fuel pump will flow less.

Higher base pressure = less flow from pump, but lower IDCs
Lower base pressure = more flow from the pump, but higher IDCs

That mbc being open like that will cause the car to fuel cut because it is causing a big boost leak...

A boost leak will cause the car to run rich due to less air entering the motor than the ECU thinks there is.

Fuel cut happens when the ECU sees more air entering the engine than it thinks it has fuel for, so it cuts off the injectors (and/or spark) to prevent engine damage due to a lean condition.

 

[LiquidX]

I would highly suggest getting a new BOV that recirculation back into the intake.

Stock injector colors are as followed
pink - 240cc - (1g 2.0Ln/t)
tan - 390cc - (1g turbo auto)
blue - 450cc - (1g turbo m/t)
black - 450cc - (2g turbo)
yellow - 510cc - (evo 1-3)
pink - 560cc - (evo 7-9)

Otherwise take a picture of the injector and any markings/words.

 

[O HAI]

get a wideband if youre gonna stick with the safc, and that T is a boost controller. The other end should be going to your wastegate. Theres plenty of write ups of how to run it correctly.

 

[Abe'sGST]

So is this a boost controller? what would happen if i removed it and run the hose from the intake straight to the bov? See when the car is running, I don't feel any vacuum from the nipple without a hose....what would be the best thing for me to do? because when i'm giving it some gas it does sound like the bov is letting air out when is boosting

And as far as the wideband and boost gauge, it came with a boost gauge and my turbo timer shows the air/fuel ratio as well and when I'm driving its pretty close to 14.7, i don't trust that though.

 

[DSMTyson]

Jesus dude.WTF

Get a vacuum hose. Put one side of the hose on the boost controller nipple that has nothing attached to it and the other side on the nipple coming off of the wastegate. Use a small clamp on the wastegate nipple if the seal isn't tight. Then turn the boost controller "righty tighty" until it stops, until you have a boost gauge that is not the factory one.

Take a picture of your fuel injectors.


vfaq.com is your best friend.

 

[bryanwheat]

The load on the injectors (and IDC's) will actually decrease as pressure goes up, but the fuel pump will flow less.

Higher base pressure = less flow from pump, but lower IDCs
Lower base pressure = more flow from the pump, but higher IDCs



A boost leak will cause the car to run rich due to less air entering the motor than the ECU thinks there is; it won't cause fuel cut.

Fuel cut happens when the ECU sees more air entering the engine than it thinks it has fuel for, so it cuts off the injectors (and/or spark) to prevent engine damage due to a lean condition.

An improperly connected MBC could cause the turbo to overrun the MAF, but it's not likely on a stock car. And, the OP's problem sounds more like the car is bogging from running too rich than it does fuel cut.

Actually a big enough boost leak will cause fuel cut. It is rather common. A smaller leak will cause a rich condition as you said and cause it to sputter and so on. But a bigger leak will cause the maf to see a way higher amount of air than what is going into the engine, it just depends on how big the leak is. The bigger the leak, the more airflow if going thru the maf. The wastegate will stay closed until the target pressure is achieved in the piping or manifold (where ever you have your source hose ran to). When you have a leak the turbo has to move quite a bit more air thru the maf in order to achieve that boost level.

 

[Abe'sGST]

So what do you suggest i should do with this boost controller? just take it off, and run a hose straight from the intake manifold to the bov? Like i said the nipple on the mbc doesn't have any vacuum so i didn't think it was leaking from there.. Thanks for all the help man