mustang notch

I have an 88 notch That will not fast idle, sometimes when I downshift the car allmost dies but then recovers and idles at 850 rpm. I have set the idle procedure many times and still the same. Here is What I got, 306 with trw pistons, e303 cam dart heads 1.6 rockes, 10.65.1 compresion, explorer upper lower ported, 65mm tb 70mm egr plate, cold air intake, 73mm air meter, 30lbs injectors with proper sample tube, 155lph fuel pump, maas air conversion with a9l cpu. I have been playing with problem for almost two years, Once the car warms up it drives just fine. Any help would be apreciated. Thanks