My engine light is on and I was told i need a new fuel pump

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.

Zafar, look in your manual for fuse/relay center, locate fuel pump relay as per your manual, purchase new relay or look at the rest of relays in box and switch alike relays to see if it makes any difference.
A weak fuel pump, acts just like what is happening to your car. I think you may need new pump.
press the helpful button and follow me on fixya for more tips and info.

I'm not sure you would smell a fuel leak from the tank while driving, the tank is located to the rear of the cab, under the bed on the driver's side, you may however have a leak in or near the engine compartment. If this is the case, yes a fire is possible. If you smell fuel when you come to a stop, it may be your fuel cannister, or vent lines are leaking which should trigger a check engine light.
While the engine is running, Check the fuel rails and schrader valves on both sides of the engine manifold for leaks. You can also turn the key to the "RUN" position (do not start the engine.) this will cycle the fuel pump to run for a few seconds to pressurize the fuel system, and you can then check for a fuel leak.
I hope this is helpful to you.

41 is injectors, 12 is

3.8 V6 runs at 30-45 psi.
some GM engines require 65-75psi

if you still have low pressure, try a new fuel pressure regulator, but a miss is usually ignition related, plugs, wires, etc.

If the fuel system isnt sealed or has a leak the check eng light will come on, so lets say they forgot to connect a line from tank to evap canister this would cause check engine light to come on, this happens no big thing as long as they repaired it at no charge. and the answer to your question is yes it can be because they didnt do the job correctly.

No need for guess work.
You can run a wire from the fuel pump positive to a dash an LED with a resister on it so it can work with 12 volts. Then you will see if the pump is getting voltage or not. This will allow you to eliminate ECU, relay, and probably the PMD (depending on exactly what that is).

But this does not discount the need to check things like the fuel filter, the gas tank vent or purge valve, etc. And you should still check the fuel rail pressure. It would not hurt to have a dash gauge for the fuel pressure as well.

First try replacing air filter if not done recently $30, next consider bad fuel put in fuel from major oil company from station with many patrons.Then you need to look at fuel delivery system including fuel filter and furl pump. But first try the 2 things mentioned.

The thing you need to do is run a leak down test on the fuel pump overnight, hook up a fuel pump test guage to the fuel injector gas rail test port, run the engine, note the fuel pressure when you shut the engine off, it should not drop more than 5 PSI overnight, if it does you need a new fuel pump. Your car doesn't use a cold start valve, that was used on very early Bosch K-Jetronic fuel injection systems, they where last used in the 80's