My 89 Iroc has started missing until warm. Its acts like the timing is turned to the bottom. It pops back through the throttle body almost like its out of time but once its hot it does more or less perfect. While its cold if you go over half throttle it takes right off. It just won't take fuel in normal driving. I don't have any codes or anything. Its got a new fuel pump, ecm, filter, regulator, ign module, cap, rotor, plugs and wires. Any ideas?