having some trouble with a truck i recently purchased. it cranks forever before it will start and when it does it misses heavily for the first 15-20 seconds, and then it will take off and run like a champ. the idle does surge from time to time. it will surge up to around a grand them drop to 200-300 rpm but it normally seems to catch itself. sometime it does not and will stall but seems to start right up and run find after.

a little background on the truck, it has sat for a long time. it only has 105k original miles on it. it is an injected 5.0 4 speed manual. when i got the truck over the winter i was having some charging problems so i replaced both the battery and the alternator which fixed that issue. once i got it home i replaced a few of the normal things not really knowing the condition of the motor. changed oil, replaced air filter, fuel filter looks brand new so left it alone, replaced plugs {checked gap on all}- wires-rotor cap and button, replaced ign coil with accel coil, new belts. there was no belt on the smog pump. it is seized up and will not move. upon having the idle and start up issues i have replaced the IAC valve, and TPS sensor. not really sure where to go from here. any advise would be appriciated.

thank you