1987 b2600 wont stay running

Hey, just recently got a 1987 b2600. And fuel pump wires have been cut somewhere from dash to pump, so ran wire right from inside to power in back pump started working and after a couple tries fired right up and idled beauty. Shut it off left came back with buddy so i could drive it home made it 100ft before lost all power and died. Fired up again gave it gas but wouldnt move and died again. Got it back to house and if you hold gas to the floor and start it, it will stay running just barely idling up and down around 300 to 500(just guessing by sound but as soon as you let off the gas it dies. Wondering if anyone can help excited about truck cause it was free but not sure what the problem is. Thanks.

It sounds like your fuel pressure blew off below minimums necessary to keep the injectors at 45psi. I know this isn't a popular opinion but get your hands on an electrical diagram and trace the problem down. You may get it to run rigged up but my guess it won't stay running for long that way.

Yea thanks, your right it doesn't run for very long first start I can drive it around for a 100ft then it just keeps dieing so I will try that.

87 2600 has a carburetor, not injectors. It sounds like you have crap floating around in the carb.

So fuel pump wiring is fine haha. My grandpa, who I got it from, thought it had no power to it and for some reason ran the wire to the tail lights. So I'm thinking carb floats are just stuck. Also most of vacuum hoses on the carb aren't on the carb and he has plugged some with pop rivets so I need to fine a hosing diagram to re hose it. So think I should remove carburator clean it and hose it properly?

Anyone know where I can get a hosing diagram for the carb. I've search the Internet but I can't seem to find one

You can disconnect the inlet for the carb and run the hose to a large container and see if the fuel keeps pumping. Maybe the vent in the fuel cap is clogged. You could try loosening the cap and see if the truck keeps running that way.