My Lexus will not stay started. I replaced the fuel pump & fuel filter. on 1994 Lexus GS300

Tried changing the battery and still will not stay cranked. Its been siting for a month now. Do anyone have an idea on what the problem could be? Please help me!

Asked by for the 1994 Lexus GS300
Was the battery dead at the first attempt to start? Can you force it to run by using gas pedal?
Yes the battery was dead and yes once its jumped I keep giving it gas but cuts back off. Could it be the IAC valve, or a relay?
Was thinking it may need to relearn idle straregy. Try to keep it running as long as you can to see if it will ever idle correctly. May take a few minutes!