IAT or MAF or MAP?? What Sensor????

MAC88 · June 29, 2003

I am trying to determine what system my truck uses toregulate fuel delivery I was considering an aftermarket

modification but I need to know if i have a IAT MAF or MAP?? the haynes manual does not list anything for my 92' GMC K2500 w/5.7 and under 8600 GVW. As always any and all help is appreciated!!!!

2001 HD · June 29, 2003

I'm not too familiar with the 92's, but the 99+ use all three.

IAT=Inlet Air Temp

MAF=Mass Air Flow

MAP=Manifold Absolute Pressure

You probably already knew this.

americanmuscleman · June 30, 2003

Mac88, TBI 350's have an IAC (idle air controller) and MAP sensor (manifold absolute pressure).

They don't have an MAF sensor (mass air flow). That was on Vortec 350's. IAT sensors (inlet air temp) are also on Vortec's.

Fuel delivery is regulated by the computer through the use of the IAC and MAP sensors. Your fuel pressure is fixed by the factory fuel pressure regulator. On TBI motors, it isn't adjustable from the factory, so you need an aftermarket adjustable regulator to make it adjustable, or make yours adjustable (someone sells a kit to do this somewhere). Your fuel is also obviously controlled by the size of your injectors, and the fuel pressure.