Isuzu trooper 3.0td 1998 turns over but will not start. I think it's a fuel problem , are they any common faults I can check?

run the fault codes and check for crank/ cam position sensors
broken timing belt, fuel problems
diesel check for air in the fuel system

which engine, ill toss coin, land on v6
check fuses first.
wont crank? that grrrrr grrrrr grrrrr sound
jumper cable start it yet, why not?
or put in a known good charged car battery?
or using any battery charger charge yours?
or buy a new battery, (if rich)

if it cranks and wont start?
check spark x6 (scan it yet?)
if sparks ok try test fuel!
if test fuel fails 100% see bad belt below.

EVER REPLACE THE CAM BELT?
if not and over 60k on the last one
the belt is doomed, living on borrowed time.
got the V6?

No its not full with diesel fuel this is a common shut off on the isuzu. Plus the valve are always noisy . The crank sensor on those go out easy.This may not be the problem.Go to the back have someone crank it ,or if your hearing is great as you crank it do you hear a hummin noise that will be the fuel pump if you dont then the fuel pump will most likely be your problem.If you hear a humming noise as you turn the key on the fuel pump will not be the problem.Now let check spark. do you have a tach on it (the RPM) if you do crank it if it bounces just a tinytiny bit you have spark and the fuel pump will be the problem. Most common Isuzu trooper failure the ignition module

they are not related ,would a better description of why its not starting to even think about a possible fault

I think you should buy repair manual first for your vehicle after that it will be easy for you to solve the problem. Check the link may be you will find something useful here
1998 2002 Isuzu Trooper Service Repair Workshop Manual DOWNLOAD

Check the fuel pump relay and fuses it may not be getting power when you turn the key on.

Clean throttle body, change fuel filter, plugs, and definately plug wires.

Egr seems to be common problem with these.

cam timming is possibly out due to gear reduction set up in heads
suggest remove rocker covers and make sure cam lobes are in this possition as well as all other timming marks luckily these engines (V6) are free wheeling (wont bend valves) set up like pic below

check your fuel delivery from the pump to the "dry" pulsing injectors leave the crank sensor alone! open the intake and, spray either (engine start) into the engine then attempt to start; it should start and, run until the either is used up then die. most likely your fuel filters are clogged

petrol?? hmm thinking about this ----if your sure that it runs on easy start then electrics ok---then it must be fuel ,right thats eliminated one thing-----now new pump and filter fitted ??is pump giving the right pressure ??was test ok.if so then ------if right pressure then its a control fault-----if not right pressure then its either pump or or non return/pressure retention valve fault.----silly question ???did you check the thin vacumn pipe that connects to the valve on the end of the common rail ,thats the bar/pipe that connects to the injectors.if this is split or porous then this will throw up the same fault.Check above out ,but without a hands on approach iam at a loss but i will think about this later as i have work in yard to do ,building an ice cream van thats demountable because of the spanish paperwork of construction and use of a vehicle.This is a silly problem as the vehicle is too old to use fancy electronics ,try looking at the thin plastic pipes and make another posting