Help fix start problem with truck

ever see the truck run perfect before, or not in 10 years?
C2500 right not k2500 ,pickup.
NO ENGINE told ,4 engines 3 gas 1diesel.
but is gas so 4 engine not told (no fun there, blind)
4.7 to 5.7L and 5.4L gas.
crankshaft and cam forgot to say sensor?
CAB means distrib CAP .
rotor sure.
why not new SPARK PLUGS first and for sure those ratty old HV spark wire, useless, I run NGK mag wires.

battery good, cranks fast and engine spins fast and does not start.
and engine compression is good
and we test that spark is good on all 8 cylinders not just one,all 8 are test
and also tested for spark timing. for sure if distributor was removed, or set loose at base and timing lost.

if all that is good the engine now runs on spray test fuel in a can. for 3 seconds, even with fuel pump fuse pulled.
if you get this far,
we check fuel pressure next and even for bad fuel.
no history of car told
bad fuel ,old rusty tanks wreck injectors.
26 year old truck,.

things bad that old are, all fluids and belts
fuel filter packed in gunk and rust.
thermostat bad.
spark parts bad, cap/rotor wire sets x8 and spark plugs. (or timed wrong or put back wrong firing order)
injectors clogged, bad fuel or rust in the tank
bad FPR, bad map sensor.(or only clogged)
or bad fuel pump if pressure is low and FPR not bad.

most of my tests all take tools and meters
a tech can not fix cars lacking his tools.
and skills to use them./
even a timing light is needed on all distrb cars
and all EFI cars a fuel pressure gauge.
and compression gauge
and vacuum gauge.

Well Dave you just can't replace parts an hope you fix it ! There are test that need to be done to find out what system is malfunctioning ! If no spark , the ignition system is at fault ! An that could be any one of a number of things , ignition control module , engine computer ,crankshaft position sensor. If the fuel system is at fault is there battery voltage getting to the fuel pump through the relay , is the PCM turning on the relay ? The relay is most often a four pin relay an where it plugs into the fuse / relay box you can test for power an ground an control of the circuit ! Another possibility would be the anti-theft system not letting it start, any light like SECURITY lit on the dash ? Rather then just replacing parts Dave in a random fashion ,you need to find out what is missing fuel , spark an is the engine in good mechanical condition an no SECURITY light ! good luck Dave !

You spent more on parts then it would have cost to take to a repair shop !

Have your ignition module checked, my car would start and drive and would go dead after a few miles and would not start until it cooled down, turned out to be the ignition module that eventually went bad and would not start at all.

Timing could be 180 degrees out try switching plug leads on distributor i.e. 1&3 2&4

I believe that motor still uses a distributor cap, rotor, and seperate coil...it has to be no spark...inspect the cap and rotor for hairline cracks...remove the coil, (Connected to center wire on distributor cap) and have tested...Hope this helps.

Since the engine cranks, the battery, starter motor/starter motor solenoid are most likely
good, so suspect everything else on the list. When you narrow it down, re-post with a
more specific question about that particular component, since 100s of components must operate
nearly perfectly for a vehicle to actually start.

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 Battery Cable Connector -- Broken/Corroded/Loose.
4 Inspect Fuel Filter -- Clogged or Dirty Fuel Filter.
5 Inspect Ignition Coil -- Faulty Ignition Coil.
6 Inspect Wireset (aka Spark Plug Wires) -- 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 Injectors -- Dirty or Worn Fuel Injectors.
16 Inspect Fuel Pump Strainer (inside fuel tank) -- Clogged or Dirty Fuel Pump Strainer.
17 Inspect Engine Control Computer -- Incorrect Operating Information Being Delivered and Sent From The EEC (faulty computer)
18 Inspect Fuel Tank -- Fuel Tank Empty.
19 Inspect Carburetor -- Carburetor Flooded or Faulty Choke.
20 Inspect Distributor Cap -- Worn, Loose, Cracked, or Incorrectly Installed Distributor Cap.
21 Inspect Distributor Rotor -- Worn, Loose, Burnt contact surface
22 Test/Inspect Neutral Safety Switch -- Faulty Neutral Safety Switch

you need to check for spark at the plugs while cranking.then check for fuel entering the intake at the injectors.you don`t say if its a 4 or 6 cylinder.if its a 4 cylinder you can look into the throttle body while someone cranks the motor and you should see fuel squirting into the intake.if you have no spark then check to make sure the cap and rotor is in good condition and the rotor is turning(if not then the timing belt maybe broken and needs replacing.also check the plugs as if they are worn so bad you won`t get any spark.a common problem on these is the coil pickup in the distributor going bad.there is a 2 wire connector that comes out of the distributor with a plug,if you follow this wire back into the distributor you will see the pickup.also check and see if you can hear the fuel pump running while cranking,you may have a bad fuel pump.you may have to remove the gas cap and listen at the filler neck or listen under the car were the gas tank is.if the fuel pump is not running then you can hit the fuel tank in the middle while someone cranks the motor and it might start.if so then the fuel pump is no good another common problem.there is a fuel pump relay under the hood on the drivers side that sometimes goes bad or there is bad connections.most of this checking is good for the 6 cylinder as well except you can see the fuel squirting into the intake.it could also be a bad computer that will have to be checked out at a shop.

could be your fuel pump relay you should check to see if the pump runes for about 3 sec. when you turn the key to the on position. It should if not the oil switch is turning on the pump after you achieve pressure.
if not check the relay. also with the pressure gauge hooked up check if your pressure drops off fast after you turn off the car. if so you need ether a pressure reg or a fuel pump.
hope this helps

Your talking about fuel pump relay,when was the last you had an tune up?wires,plugs,rotor,cap,fuel filter?

might look at the spark plug wires and plugs make sure none of the wires are burned or cracked destributer cap could also be a culprit or the rotor or the coil .