Help! Rough Idle

[elcaballo96]

I just ordered a maf sensor and installed it on my mustang. I used to have the factory maf sensor and switched it to a bbk 76mm maf. I have a 1991 mustang gt with 24lb injectors. The problem that I'm having is rough idle. I let the computer re-adjust by disconnecting the battery, but I am still expiriencing the rough idle. My car ran perfectly fine before upgrading to the new maf. I already bought new fuel pressure regulator and adjusted it from 40- 50 psi, with no luck.

 

[madspeed]

well I can tell you that your computer will not play nicely with the 24# injectors, but.... run a search for the idle surge checklist. Followthat precisely and you'll be fixed up in no time!

 

[elcaballo96]

well I can tell you that your computer will not play nicely with the 24# injectors, but.... run a search for the idle surge checklist. Followthat precisely and you'll be fixed up in no time!

Yeah man i already fixed it. Turned out I had my cold air intake inside my engine compartment instead of the front quarter panel. So my maf was picking up the hot air that my fan was blowing, causing it to malfunction. Thanks for the advice though. She's running perfect just a little rich. how would I be able to adjust that. Should I turn down the fuel pressure? I also have the a9l ecu so I don't think it's my computer.

 

[madspeed]

It is running rich due to the 24# injectors. Even with a calibrated maf, it is just a bandaid to trick the computer. At your mod level, stock 19# injectors and maf are plenty. i would keep the fuel pressure set at 39 psi