98 GT ran great when I put it on jackstands a year and a half ago for a two month project. Finally got it on the ground. Fuel pump didn't work, so replaced that. Fuel filter has less than 2,000 miles on it, was clear when I put it back last month. The car will fire up, but won't idle. The rpm would peak up to 3k then drop down, stumble, and die once started even with no throttle. Touch the throttle, revs super fast but won't steady at any one speed. I checked for vacuum leaks. Replaced the IAC, almost no improvement. Touched positive and negative battery cables together for 30 seconds to reset the computer on advice of my local mechanic. It is better, will idle rough for 30 seconds before dying, still revs too high if I touch the throttle. Stock except for Accufab plenum and 70mm throttle body that was rebuilt and calibrated at the factory before install, BBK CAI, Ford Racing wires, Screamin Demon coils. Ran great when I parked it. I'm out of ideas. Any suggestions?