safc

[chehsgsx]

ok so i have fuel cut and i know a safc can help with that, now should i get an apexi safc ll or the nero one. some people say the older one is better what does everyone think. also in order to fully resolve my fuel cut this would have to be paired with bigger injectors rite?
im very new to fuel cut but have read to good post about it. just wanted to make sure im heading in the rite direction.


thanks for the help

 

[winterftbl]

Yes you need bigger injectors for the safc, also you need a logger to see whats going on. But do a blt first to see if that is your problem. Hope that helps.

 

[Zmann42087]

ok so i have fuel cut and i know a safc can help with that. also in order to fully resolve my fuel cut this would have to be paired with bigger injectors rite?.

Fuel cut occurs when the MAF is seeing more airflow than the car was designed for. Consequently, the ECU removes the injector firing signal and your car hits the "wall" that is so commonly associated with fuel cut. Yes, one remedy is to use an Air-Fuel Controller. An AFC just manipulates the airflow reading from the MAF before it gets to the ECU. By using the AFC to reduce the signal from the MAF, the ECU will see less airflow and won't cut out the fuel. Of course, reducing the airflow that the ECU sees will reduce the injector pulse which means less fuel delivered. This would be fatal if you still have the stock injectors as you would be knocking like crazy. However, if you upgrade the size of your fuel injectors, this reduced injectors pulse can be used to control the larger injectors. Up to 680cc injectors can be safely controlled using an AFC. Note that you'll need an OBDII data logger at minimum so you can watch for pulled ignition timing (knock) when you're making adjustments on the AFC. A wideband O2 is always a good investment as well.

now should i get an apexi safc ll or the nero one. some people say the older one is better what does everyone think.

Get the SAFC or SAFC II. The new(er) Apex'i NEO doesn't work with our cars or any vehicle equipped with a Karman airflow sensor.

Apex'i NEO Karman Airflow Problems
Apexi NEO Important Info
Calling All NEO Users. Need Feedback On If This Happend To You..

 

[No_Skillz]

Your fuel cut is saving your motor.

Like Z said, fuel cut happens when your ECU reads more airflow from your MAF than it thinks the stock fuel system can handle and shuts everything off before something blows up. A 2g MAF and stock ECU, however, can provide much more fuel than what your turbo is capable of putting out (seeing as you are on a stock turbo). The most obvious assumption is that you are not actually flowing that much air into your motor but have severe boost leaks.

You don't need an AFC, you need to do some basic maintenence. Start with a BLT.

 

[chehsgsx]

i have no leaks, thought that's where my first fuel cut came from. im not running much boost either just the amount the computer says.( do not have a mbc), though i did take the little black restriction out of the controler to get a little more. im running about 15 pounds. soo then y do i have fuel cut???? after i fixed all the boost leaks over the summer the car ran great.. now it started to get cold and it came back??/ whats up with that???
ohh as a side note my thermostat was leaking so the car never really warmed up, could this cause fuel cut???? iv replaced it now but im scared to just go out and floor it,,, fuel cuts violent .

the only mods done are my tunderbird intercooler the little extra boost a good bov(venting back in) and an exhaust (that leaks at the o2 a little!!!) i cant understand hitting fuel cut with this minimal amount of mods?!?!?!?

 

[chehsgsx]

does anyone know if thecar not coming out of warm up will cause fuel cut????

 

[No_Skillz]

does anyone know if thecar not coming out of warm up will cause fuel cut????

I have never attempted to boost while the car was not warmed up for obvious reasons, therefore I can't tell you what the car does.

However, I CAN tell you that if your coolant temp needle is sitting steady around the middle of the gauge, chances are the car is warmed up. However, it's a good idea to invest in a logger to look at coolant temps since the sensors running to the ECU and gauge are different and one of them may be malfunctioning. A logger will also make fixing this problem much easier.

You need to get a boost gauge. You think you are running about 15PSI, but what if your wastegate is actually stuck and you are running 25PSI?

When you did your BLT, did you reach 20PSI and how long did it take to leak back to 0?

 

[chehsgsx]

i have a logger but it cant monitor the sensors in real time its more of a ob11 scanner but it does freeze frame when the code was found and gives u rpms, and temps throttle position things like that.

im 99% sure that im pruning 15 pounds because i have a gauge cluster out of another car (its got a manual boost gauge wit numbers) and i use that after any mods just to check that boost is in spec.. but i agree i really need a boost gauge to monitor it at all times.

when i tested for leaks it held 20 psi for a a while. dont really know how long though but it wasn't like 10 sec latter there was no pressure again it held it.

 

[No_Skillz]

When the car is warmed up, drive it around and take some captures of coolant temp readings.

 

[chehsgsx]

well the gauge reads an ok temp.. but idk how reliable that is. but it does stay in the middle with no fluctuation. iv come to believe that there something else acting up... tonight on the way home and i didnt have that violent fuel cut but it felt like the car pulled timing out i really want to see the a/f readings but i dont have a gauge ( by the way order my boost gauge last night ) is there a way to read the voltage coming outa the o2 sensor and convert that to a/f ratios kinda a fake wide band? any one know? im really at a loss here

 

[spyderturbo007]

I'm late with a response, but it seems your question wasn't answered.

There is no way to use a narrowband sensor to get AFR. Even attempting an extrapolation from the sensor voltage is going to introduce an excessive uncertainty into the calculation. You need to resolution of a WBO2 sensor to get AFR.

Nail down your boost leak because there is no way you should be hitting fuel cut at 15psi on the stock turbo. You should also invest in a logger.