1987 Oldsmobile 88 wont run for more than 3 secs

Wow what a car, started out the seller said only the starter needed replaced. Well once it was done still wouldnt start, so we replaced the burned up fuel pump(twice) still wouldnt start. Went on to cam, crank sensor both plugs wires ecm tps, maf. Will now fire just wont continue to run more than 3 secs. Fuel pump is real loud and runs non stop while trying to fire. We tested the ign module and it tested good. Could you plz tells us the next step to look at. If we catch the throttle under the hood fast enough, we can keep givin it gas and it will run but as soon as we let go or stop it shuts down.

Thank You