Fuel pump without enough psi. suggestions??

Check the fuel pressure at the engine and plugs for spark (ignition module).

"All cylinders have 120 psi compression." I would be seriously concerned about this. Typically, an engine's compression should be much higher e.g. 180 psi or more. Could mud have gotten into the exhaust system causing restrictive back pressure?

fuel filter first, then fuel pump. check relays and fuses. Bleed air from fuel rail and check for injector o-ring leaks

Check for proper ground to fuel pump. did you replace the fuel filter? idle air control valve may be sticking or you have a vacuum leak.

Whe you turn the key to the on position you should hear the fuel pump working for about 5 seconds. If not replace the engines oil pressure switch for the fuel pump is linked to this part. Once the engine reaches normal operating oil pressure the computer shuts the circuit off to the third wire from the oil pressure switch which is linked to the fuel pum feed and the computer then turns on the fuel pump relay to operate the pump

SOUND LIKE FUEL PUMP FAULTY.CHECK FUEL PUMP PRESSURE. IT SHOULD BE 35 - 45 PSI.

try eather spray it in the air filter box then try and start if it starts then your not getting enough foule.

lifting the truck bed off the frame works best if you dont have a lift..take the fuel neck loose from bed and remove bolts holding bed to frame from the drivers side..loosen the bolts on passenger side..raise the bed on drivers side while watching bumper to bed clearance on passenger side.. you should get enough clearance to remove fuel pump from tank

theres 2 options,voltage feeding pump is fluctuating,or pump itself is going bad!

if it is the fuel level sending unit you will have to replace the pump because they are a 1 piece assambly. it will be a task to change too as you will need to either remove the truck bed or drop the fuel tank to get to it.