97 chevy cargo van 5.7liter engine. Replaced fuel pump, dist.cap and rotor, spark plugs and wires air filter and oil change and oil filter. Will crank but won't start. Tried putting starting fluid air filter. Turned over once but died right away and won't start after that.

might pull that cap again and see if the dist. shaft is loose
(side to side play) Sometimes the bushing wears out and the
magnet will hit the pickup,makes the spark irratic.Should have a new rotor with the cap,they also go bad.

You've already eliminated the spark plug & wireset, distributor cap & rotor.
Sounds like your car needs a tune-up, specifically, the PCV (positive crankcase ventilation) valve, and/of the EGR (Exhaust Gas Recirculation) valve.

Components checked/replaced during a tune-up are:
air filter
motor oil
motor oil filter
breather filter
fuel filter(s)
fuel strainer
PCV valve
EGR valve
spark plugs
spark plug wires
ECM or distributor cap & rotor
cabin air filter
transmission oil filter
transmission oil
engine coolant
check all vacuum hoses and lines

Troubleshooting the no-start condition - from the 1990 Mitsu Mighty Max Repair Manual:

Priority Action Part Type -- Cause
1 Inspect Battery -- Battery Discharged or Faulty.
2 Inspect Battery Cable -- Corroded, Broken, Shorted or Poorly Connected Battery Cable.
3 Inspect Distributor Cap -- Distributor Cap Cracked or Burned.
3 Inspect Fuel Filter -- Clogged or Dirty Fuel Filter.
5 Inspect Ignition Coil -- Faulty Ignition Coil.
6 Inspect Wireset -- Worn, Damaged or Faulty Spark Plug Wire(s).
7 Inspect Spark Plug -- Incorrectly Gapped or Fouled Spark Plug(s).
8 Inspect Starter -- Starter Motor Faulty.
9 Inspect Fuel Pump -- Low Fuel Pressure.
10 Inspect Solenoid Switch -- Faulty Starter Solenoid Switch.
11 Inspect Fuel Pump Relay -- Faulty Fuel Pump Relay.
12 Inspect Fuel Injector Pressure Regulator -- Faulty Fuel Injector Pressure Regulator.
13 Inspect Ignition Switch -- Improperly Connected or Faulty Ignition Switch.
14 Inspect Starter Drive -- Faulty Starter Drive.
15 Inspect Fuel Injector -- Dirty or Worn Fuel Injectors.
16 Inspect Fuel Pump Strainer -- Clogged or Dirty Fuel Pump Strainerat.
17 Inspect Engine Control Computer -- Incorrect Operating Information Being Delivered and Sent From The EEC.
18 Inspect Fuel Tank -- Fuel Tank Empty.
19 Inspect Carburetor -- Carburetor Flooded or Faulty Choke.
20 Inspect Distributor -- Worn, Loose, or Incorrectly Installed Distributor.

I would change the spark plugs, spark plug wires, distributor cap and rotor, fuel filter, check and change air filter if dirty, check timing, check and top off all fluids, check or change transmission fluid, check brake pads/.shoes and drums/rotors for wear and check tire pressure, check the condition of all belts and hoses and replace as needed, check condition of radiator antifreeze and top off or replace as needed.

time to buy a new van.. umm what about the alternator?

1/ Have you fitted the spark plug leads in the proper firing order.
2/ Look inside the top of distributor Top (this is not the first time a new distributer cap has very small crack) or the rotor arm is fitting the cap properly. Hope this helps Best Wishes, Malcolm Campbell.

Start with fuel system. Listen for fuel pump humm at fuel tank No humm check wiring to pump for power. Then check for spark at plugs and wires. Remove wire from coil and hold near engine and see arch when you crank. No arch. Replace ignition Modular inside distributor cap or cap or rotor

replace carbutator and get it profesional tunned

AM temp 55 car started but stalled out after starting. Attempted to restart and did not hear fuel pump. Tried again and then fuel pump kicked in. Checking fuel pump inertial switch and fuel pump electrical supply.

Fuel Filters need to be changed EVERY 15,000 Mi and oil changes once a year maybe,maybe every two years
Common Problem for the cargo is that the distributor gets moisture in it due to the vent being plugged up, And the Cap and rotor have been Known to cause your symptoms use only GENUINE dELCO PARTS IN YOUR VAN TO ASSURE THE PROPER PERFORMANCE

buy a Honda or Toyota, they work