What causes 350 on a chevy c1500 1996 to start

The Chevy's had a stock fault with the ignition switch. they issued a recall some three years ago. Check with your dealer.

I do know that when your antitheft system fails, you will get exactly what you have. Turn key, starts for 1-5 seconds, then stalls. This will be followed by a light illuminating on your dash that says SECURITY or ANTITHEFT. If you see this light, go to this link for help.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

When the engine dies do the accessories such as radio, lights, heater all die along with the engine; or do they keep running as they were prior to the stall?
If they all quit together (as if the key was shut off) I would check the electrical part of the ignition switch or the battery cables and connections (check both ends of cables and little ground wire near battery that connects to car body). The ignition switches are a well known culprit in the s10's.

If the radio and lights keep running after the stall, I would look at the crank position sensor, ignition coils etc.

Good Luck!

Fuel pump. Not cheap and you'll need to remove the bed to change it. Not hard to do. Remove bed bolts and just lift the driver side. If you jump right in it only takes about an hour.

a likely problem is a fuel pump going down...as it gets warm, it heats up the wiring inside and they expand causing a loss of connection inside the pump...As it cools, it comes back together and works again...when it dies out turn the key off and listen closely for the pump to hum when you turn the key on...If it doesn't wait for it to cool and then when you try again listen and if you hear it and it starts, that's your problem...fuel pumps will go bad quickly if you don't keep your tank at least a quarter to half full as the gas is what keeps it cool so it don't get too hot and melt the shellac on the wiring which will eventually short out...

You need to find oput what you loose when the truck shuts off, all you need is Air, Fuel , and spark to run one of the three are droppuig out when it stalls and will not run. Chech the carb for gas it sounds like you have a weak fuel pump.

Check your fuel preasure. Maybe fuel pump.

Yes a fuel filter can cause the problem but I would say it's most likely the fuel pump or fuel pump relay. Can you hear the fuel pump running when you turn on the ignition?

first, turn the key on, but do not crank the engine. do you hear the fuel pump run for about 2 seconds?