91 3500 chevy dually that has been sitting for 3 years. After starting it runs and dies at idle. It will run at 2000. We tryed a map and new injectors. The fuel pressure is at 15 lbs. We also pulled the intake and put new gaskets and tbi base gasket. It has new cap rotor and wires. Tp reads good. Has code 44 for rich exhuast but I believe it is wrong. It will run fine over 2K.

3 year old gas?? 15 psi at idle I believe is high check the specs, should be about 10-13, 10 at idle, of course the gage could be a little off, make sure good vacuum to the map sensor, also. Try cleaning the iac, make sure the egr is seating, lots of possibilities here.

it is 454. Blocked off egr and tryed a different iac. Tryed a different fuel regulator and it was 13 and no change. Egr is working and good vacumn to map.

Still looking for a little help. Have replaced injectors, ecm, regulator, oxygen sensor, tbi base and intake manifold gaskets. Checked powers and grounds. Truck runs fine over 1500 rpms and backfires like mad below and wont idle on its own. Will flame out tbi when back firing. O2 sensor was bad and now switches correctly but still wont idle. It acts like vacuum leak. It also had new IAC and Egr is plated off now. Ect is working correctly.

Bad distributor. Fixed! Cracked in magnet on shaft?