Chevrolet Celebrity Forum : “car starts runs about 20 seconds then dies but start up !”

car starts runs about 20 seconds then dies but start up !

I have put on the following parts,ecm,ing mod.,ivac,map sensor,fuel pump,fuel regulator,egr. Checked fuel lines ok.Tps sensor ok. Car starts run 15 to 20 seconds and dies out but starts right up. If you push on gas pedal it dies??