1999 Suburban doesn't want to cold sta...

My Suburban has a rebuilt engine with only 14,000 miles on it now. We put in a new ignition switch because thats what the dealer said their computer said it was. It started just fine for about a week. We have ALOT of trouble starting it in the mornings. IF we are lucky enough to start it, it spits and sputters until its completely warmed up then we run it for awhile...it starts everytime with no problems at all!! We also changed the fuel pump, fuel filter, coil, ignition module, camshaft and crankshaft sensors and the mass airflow sensor....its driving us crazy!!!! HELP!!