What would prevent fuel injectors from getting fuel

Silverado 1500 or 2500 or 3500 or HD? no pickup told
not told the job you are doing>??
remove them all ,or scope them or just what, no job told
no end goal or task told. sorry can guess it.

like most V6/8 now , it is a sandwich.
the service manual covers all,l buy it rent it.?
toss dice and land on 1500
the rail on this engine, fuel rail like all , intake manifold injectors used;. all injector held down by both rails. left and right
now the steps to off them if is the job,
pull the isolator seen photo 1, far below.
1: pull left rail and right rail
Remove and discard the fuel injector retainer clips by installing EN-51097 injector retaining clip installer and spreading both sides of the clip evenly.
Always use NEW fuel injector collars supplied with injector when installing the new injector. If reinstalling the injector, it is not necessary to remove the collars unless the collars are being replaced.
Replace the injector seals as needed. Refer to Fuel Rail and Injectors Cleaning and Inspection.
Note
Inspect the injectors to be sure that they are clean and free of debris prior to installation. Do NOT lubricate the injector seals. Rebuild the fuel injectors whenever the injector has been removed from the fuel injector rail.


now I will past the other page rails off per the manual read to you.
just bank 1, i am to lazy to post both
step 1 rail off bank1.
Note
Inspect the injectors to be sure that they are clean and free of debris prior to installation. Do NOT lubricate the injector seals. Rebuild the fuel injectors whenever the injector has been removed from the fuel injector rail.

1. Remove the fuel pump insulator. Fuel Pump Insulator Replacement
2. Remove the fuel injector intermediate pipe position?1. Fuel Feed Intermediate Pipe Replacement - Position 1
3. Clean the cylinder head pocket around the injectors of any dirt or buildup.
4. Disconnect the electrical wiring harness connectors from the fuel rail.
5. the fuel rail fasteners are retained in the fuel rail by keepers and may be difficult to remove.Remove the fuel rail fasteners?(1) securing the injector rail?(2).
   Install two sets of EN-49248 remover?(3).
6. Install one remover in each of the fuel rail fastener bores.
7. Remove by turning each section of the EN-49248 remover an even amount to pull the fuel rail and injectors out evenly.
8. CAUTION
9. Remove the fuel rail assembly carefully in order to prevent damage to the injector electrical connector terminals and the injector spray tips. Support the fuel rail after the fuel rail is removed in order to avoid damaging the fuel rail components.
10. Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering open pipes and passages.
11. 1. Simultaneously lift both ends of the fuel rail?(2) and remove the fuel rail assembly from the cylinder head.
12. Remove and DISCARD the fuel injector seals.
13. Some vehicles were not originally equipped with fuel injector dust seals. A NEW seal must be installed when the injectors are removed.
    Remove and DISCARD the fuel injector dust seal (1).
14. NOTE
    Note
    Whenever the fuel injectors are removed from the cylinder head or fuel rail, they will need to be rebuilt. Fuel Rail and Injectors Cleaning and Inspection
    If replacing the fuel injection fuel rail, remove the fuel injectors. Fuel Injector Replacement

Installation Procedure, skipped me. the service manual lists 4 tools
per

Special Tools

1. EN-49248 Injector Rail Assembly Remover
2. EN-51105-1 Injector Seal Installer and Sizer
3. EN-49245-3 Fuel Injection Seal Installer Sizer
4. EN-49245-4 Fuel Injection Seal Installer Sizer

this is first. pull the isolator.

this one step is the GET TO ANSWEREd
Injector work 10x more complex and special tools needed x4

1. Clogged Fuel Injector: A clogged fuel injector can cause a misfire, which can prevent the spark from reaching the spark plugs. Check to see if the fuel injectors are clean and working correctly. ????

WRONG !

You will only get fuel at the injectors when cranking, the pump wont run(Usually) with just the key on. This is to prevent the pump running in a crash and feeding the engine.

It is called pulse. Lack of pulse to the injectors is a wiring problem or a Powertrain control module problem. You should have 12 volts to one side of each injector with key turned to run, do you?

One thing with diesels they do not like short trips and what I mean by short trips the vehicle needs to be started idle and driven for a minimal of 40 minutes 4 engine to fully heat up to prevent excess carbon build-up and if it has a lot of miles on it you are exhaust could be getting plugged up or restricted especially if it has a a catalytic converter on it if it's plugged up with suit you will get bad fuel mileage much same thing with your air intake a dirty air filter can rob you of power and fuel efficiency same thing on the exhaust side if a diesel can't breathe then it will gobble up more fuel then it needs and diesels need to have fuel treatment / injector cleaner that is meant for diesels ran through them at least every third fill up to prevent the injectors from getting clogged which will damage fuel efficiency and help prevent burning holes in your Pistons which is true with any injector gas or diesel and from my Google search of your vehicle the 3.2 L sized engine gets about the fuel mileage that you say you're getting if it's the 2.2 it should be getting 20 two 25 City and 38 to 40 Highway

The regulator may have locked up preventing anything to pass. It could also be a clogged filter. Those are two of the biggest reasons why fuel wont get to the injectors.

HELLO you don't need to replace injectors unless you have one completely plug, Just get a pressurize fuel injection service done that will bring your injectors to top shape . hope this helps

no, the fuel injector being plugged is likely not to affect the other 3 on the same side from getting fuel.

The fuel rail is really large in diameter compared to the orifice of the fuel injector.

If the fuel rail were plugged up, it would mean nothing would get through to the injectors, which generally does not happen.

you may indeed hear it running but there is a plug that pops out preventing flow.
replace pump.

To Install:

1. Lubricate the NEW fuel injector O-rings with clean engine oil.
2. Install the O-rings on the fuel injector.
3. Install a NEW retainer clip on the fuel injector.
4. Install the fuel injector in the injector socket with the electrical connector facing outward. The retainer clip locks onto a flange at the fuel rail injector socket.
5. Install the fuel rail.

NOTE: Use care in removing the fuel injectors in order to prevent damage to the electrical connector pins on the injector and to prevent damage to the nozzle. Service the fuel injector as a complete assembly only. The fuel injector is an electrical component. DO NOT immerse the fuel injector in any type of cleaner.