1996 Pontiac Firebird.. trouble starting!?

[Enjoi]

i feel it may be because of the security light.
i sat without a battery for a couple of months.
put a new one in
tries starting up, but kinda.. sputters.. need to keep pressing on the gas.
the tank is three fourths full.
fuel pump should be fine..

so how do i disable the security thing?
oh yeah, the security light stays on.. no blinking
i kept the key turned foward.. for about twenty minutes..
it never went off.
yeah, it'll go like
puf puff pufff.. then stop..
when i give it gas.. keep pressing it.. it'll stay on for longer.
i'll look into the other things you said!