Yep getting the common fuel cut. 1st and 2nd gear are fine but when i floor it in 3rd i reach about 6k rpms (peaking and holding at 18psi).. and POOF! Fuel Cut nasty style. Now i Just installed a turboback, walbro fuel pump, and mbc.... now i kno its not the turboback or the intake/bov (cause they worked fine before)... im thinking since the extra fuel is commin in (walbro) it mite be causing a boost cut.. but is that even possible and im only at 18psi!?... I kno people say flash it or check for boost leaks but i checked and everything is fine..... So ive come to a conclusion that it has to be the mbc... im going to take it off tomorrow and leave the stock boost solenoid and see wat happens.... any help or responses i can use? THanks guys

 

your boost gauge may not be reading accuratetly imo, did u check it?

 

Yeah i checked it through my turbo timer that also reads boost... but ill use my friends defi gauge and triple check just to make sure.

 

Did you get it tuned after installing the fuel pump? You could be running really rich and maxing out your injectors.

 

Gah. Why do people do all these mods without a tune? Are you saying you have exhaust, mbc, intake, and fuel pump without a tune. WHy would you add more fuel to an already rich stock tune? Baffling.

Ok, listen, it's not your MBC...it's not any of your mods individually. It's all of them combined. Fuel cut is simple. It is caused when the MAF detects a certain amount of airflow that is beyond its built-in safety threshold. It is not based on boost levels, although airflow volume is directly related to boost. You may only peak at 18psi (not sure why, since that's less than stock), but if you're still at 18psi by 6krpm, then you're getting some good airflow. The more dense the air (cold temps, near sea level), the more airflow volume you'll have. Without a flash or some tuning device that removes fuel cut, this will continue regardless of the MBC.

 

Fuel cut is based on airflow, so something is telling the ECU that you are pulling alot of air. Try turning your boost down and see if the issue exists. If you are getting this in 3rd, then you will get it very quickly in 4th. Also, if you hit fuel cut a few times you will generally throw a cell light that will say Overboost condition if you scan it. If you arent getting that, then it may be something else. Ive never maxed out my injectors, so I dont know if that could be causing it, but I dont think you have the required air flow to be maxing out your injectors anyway.

 

So do u think if i take off the stock fuel pump and boost regular it shouldnt be fuel cutting... i kno i need a flash/tune or watever but wats the point if im still going to be putting on more parts

 

Check the airflow sensor itself. We're seeing more and more dirty ones causing faulty readings and allowing fuel cut to hit with relatively low boost levels.

 

are you sure it's there's not a boost spike when this happens?? i had the same problem with spikes making me hit fuel cut...

 

This isn't a spike issue. This is at higher rpm where boost is steady. At higher rpms with more load in higher gears, there is much more airflow. If you ever get to see your MAF HZ with an SAFC, you will see that the airflow at 7000rpm and 18psi is much higher than 4000rpm and 22psi (same gear). Fuel cut usually happens at higher rpm in 3rd gear or higher with healthy boost, but the actual boost level is dependent upon the car itself, its mods, and the air density (air temp/altitude).

IntegX, no, it's not the fuel pump and MBC...it's your lack of tune and high amount of airflow. The first thing I'd do is get a tune. You can get tuned again later...no sense in running around with a crappy car.

 

What is the reccomended method for cleaning the maf sensor?

 

Remove the sensor assembly (ideally seperate from the airbox) and clean with this (or something similar): http://www.crcindustries.com/hd/cont....aspx?PN=05110 You may also want to clean out the intake tube as those get pretty dirty in conjunction with the sensor.

 

a good piece of info