Mitsubishi Repair: fuel injector problem, vacuum leak, head gasket

Question
Dodge ram 50, which is a mitsubishi motor, 1992 2.4 liter FI:: #1 cylinder injector pulse is there when the motor is cold but when the motor warms the pulse to #1 injector stops and the motor starts missing. Injector has been replaced, and a test light shows no pulse when the motor is missing. ECU computer replaced, distributor replaced.  

Answer
James: Going to just pull this right out of my repair manual, with ideas to check... vacuum leak, leaking EGR valve, fuel pump not pumping out enough fuel, leaking head gasket, timing belt or pulleys worn, camshaft worn, incorrect ignition timing and uneven or low compression. So there are some ideas to check and I hope one of them helps you out. God bless: Linda