not nescecarily a fuel issue.... but sounds like an air/fuel mix issue
for ANY no start issue on ANY engine follow the easy method
suck, squeeze, bang, blow.
the basics an engine needs to run..
check it has all of these parts working correctly to find the cause
these have sections on modern engines for anyone who cares....
signal to start ok? (immobiliser starter ecu power and earth etc)
voltage high enough to stay cranking? (battery altenator or starter or siezed motor)
air getting in? (blocked intake)
air in being measured correctly?(afm or map sensor or intake leak)
fuel? (sender failure or pump or fuel pressure reg)
fuel pressure ok? (check at rail)
fuel injector signals ok? (noid light check and or cas)
injectors ok? (leaking or blocked)
compression? (also shows if timing is out mechanically/internally)
spark? (check coils leads plugs)
exhaust unblocked? (blocked cat or dpf)
exhaust air being measured? (02 sensors)
ignition on signal maintained? (relays ecu's ignition switchs key readers etc)
but anyways im done blabbering
FOR YOUR CAR THIS TRANSLATES TO
as it starts AND RUNS FOR 5 SECONDS then stalls likely immobiliser is not stalling it as it would just not start at all and just crank....and engine light flashes while cranking????? from memory~! key reader is part of the immobiliser signal circuit......
recomend a
code check for starters..........(look it up in search up there^^^^)
note: (afm doesnt always set code if dead OR WET WITH WATER/OIL)
i would check the
fuel tank isnt empty... put ten litres in and retry... if works sender is dead or your blind
if started
AFTER you replaced pump then skip this one
if this issue was there
BEFORE you replaced the fuel pump
then maybe
air flow meter is incorrect reading to engine control module
(as in when you said "
you apply accelerator it stalls straight away" this is a cause OR fuel pressure)
check fuel pressure would be my next check.... as maybe there is a blockage or regulator dead or pressure too high OR too low (incorrect hose connections OR incorrect fuel pump requiring adjustable fuel pressure regulator)
(as in did replacing the pump fix the issue you replaced it for or cause this one?)
if
afm and
fuel pressure and
no codes is all ok
check for a vacum leak AFTER the AIR flow METER hoses on inlet manifold etc (bit of carby spray around them all will show you IF there is a vacum leak)
then maybe spark cutting out after a few cycles (normally just straight out die but NO START only crank)
code with this normally-->
crank angle sensor...
I
would check with a scan tool if there is an rpm signal from crank angle sensor before declaring it dead....
next for me if all that was ok would be a
compression check......
to make sure your not chasing an internal pressure issue or timing issue (chain cam etc)
if none of this fixes it you have missed something....... pm me if stuck still.....
OH and i know people have there own ways of diagnosing things but generally what i have said is the basic steps i follow when i have an issue..... so if you dont like how i do things dont tell me......
