Truck cut off while running. No fire and no fuel pressure

The Vehicle Control Module (VCM) electronically cuts off fuel to injectors when engine speed exceeds 5500 RPM . You should hear fuel relay click on firewall when key is turned on . Esay way to check fuel pressure without proper gauges is to diconnect fuel supply line at engine and cycle key , Have plenty of rags around fuel line .

turn key and listen to fuel pump if will hum meaning its pressuring the line --if sounds erratic possible going bad may need replacement --check fuel pressure valve by fire wall if weak or sputter either fuel filter or pump---also need to check egr valve if it carboned up or has failed may need cleaning or replacement

Sounds like your approach has not been successful
because you change things in hope of a solution

You have to gather the facts based on what it does
or doesn't do,then do some testing on what does work
As your proceeding you will eventually find something
that isn't right. Maybe the fuel pump etc.

I don't mean to be negative toward you in any way,but
you need a good understanding of the basics and the
ability to use a volt meter etc.

When you say you have spark,gas etc,you may well have
But is it weak spark,is it correctly timed,is fuel pressure
correct.

For the future---forget the tune-up and spark plug thing
You could throw away one or two plugs and it would start

to run an engine needs 3 basic things fuel air and spark. you have spark so next step is to see if you are getting fuel to your cylinders i am guessing it is injected so you should check fuel pressure in your fuel rails. if you are gettign fuel then last thing would be air but is highly unlikely i would say no fuel

the usual would be check fuel pump/fuel filter [no fuel pressure try spray starter fluid if fires up -u have fuel problem-turn key on listen for hum of pump no hum check fuses and wiring /connectors -if hum check fuel pressure to throttle body if no pressure turn off and test pressure before filter if good replace filter if no replace pump and retest-if u had an electronic /sensor problem would show up as a check engine light

Have you checked your cranck sensor located behind balancer? that is a common thing it seems with that car.

WHAT I WOULD DO IS TEST THE FUEL PRESSURE SOME TIMES THE PUMP WILL PUMP ENOUGH FUEL TO GET TO THE TBI BUT NOT ENOUGH TO FIRE THE TRUCK. IF FUEL PRESSURE IS GOOD REMOVE THE DISTBURTOR CAP AND INSPECT THE CAP AND ROTOR, CHECK FOR CORROTION N EITHER ONE SOME TIMES IS BUILDS UP AND STOPS THE SPARK. GIVE THAT A TRY GOOD LUCK HOPE THIS HELPS.

I have had this problem on my 89 and my 94 gm trucks what it was is the pick up inside the distributor time to rebuild it (not the cap and rotor) the little thing inside with all the wire wrapped around something- copper wire with a clear coating on it the coating get hot and cracks causeing it to ground out when the vehicle warms up run ok until u shut it off then no start or runs rough

CHEEK FOR BAD PLUG WIRE DONT TAKE MUCH AND TRY THIS AFTER DARK CHEEK UNDER HOOD U CAN SEE THE SPARK BETTER SOUNDS LIKE IT JUMPING FIRE I HAD A GRAND PRIX 73 MODEL WHIN I WAS YOUNGER IT DID THAT I LOOKED UNDER HOOD AFTER DARK MAN IT LOOKED LIKE CHRISTMAS TREE BAD WIRES WILL MAKE IT CUT OUT GO BYE SOME FROM NAPA I BET IT WILL CHANGE IT IF ITS FULL ING TRY CHANGING YOUR TPS SINCOR AND ANORHER THING FROM WHAT YOUR SAYING SOUNDS LIKE IT MAY BE JUST A TAD OUT OF TIME LOOSEN THE NUT UNDER THE DDISTRIBUTOR TURN CLOCK WISE JUST A LITTLE SEE IF IT GET BETTER

Check for fuel pressure when starting. Fuel pumps have a check valve in them that keep fuel in the rail at the injectors. If the check valve fails, the pump has to pump fuel all of the way up to the engine. Same thing with hot no-restarts. Fuel pump.