Background. I just bought my first Mustang. It is a 93 LX with tons of mods. GT40 heads, 30lbs injectors, V1 Supercharger, Holly lower intake, Cam, bbk 70mm throttle body, and some other stuff. Here is the ad where I bought it. http://imgur.com/eLn8vKN


After sitting for a few hours I have to give it gas for a few minutes to keep it running otherwise the RPM's will drop <700 and it will die. I took it into the shop and the mechanic replaced the Idle Air Control valve with a stock one. This didn't fix the problem and I think it may be the Mass Airflow Sensor. It has a stock sensor but is running 30lb injectors and a V1 Supercharger. I called the mechanic and he told me it would need a different IAC because of the charger but that sounds like BS to me. He was recommended by my dad but I am not impressed. Anyway, I can see the sensor and it would be easy to replace I just need to know which MAF sensor I need to get. And also will I need a different IAC valve because of the SC?

I performed the koeo test. It gave me codes 31, 81, and 82. It froze here for about 5 minutes and never put out the separator code or the cmm codes. In addition when I performed the koer test it did nothing until the tester eventually turned off. I looked for the EGR and it has been removed but I guess not deleted from the computer so I'm getting the code. Any way what should I do here?

 

Some people purchase an IAC adjuster plate that allows fine tuning of idle with forced induction applications, but your problem is the MAF. You need one calibrated for 30# injectors.

 

I agree with mattdel

either get a maf that is calibrated for 30lb injectors or at least get a maf housing that has a 30lb sample tube.

I run 30s with stock maf, but I have a C&L maf housing with a calibrated sample tube.

 

I agree you need a larger MAF, but you also need a dyno tune with chip for the supercharger. Find someone in your area that has tuned Fox Mustangs with superchargers before.