GMC Troubleshooting Questions? Ask a Mechanic for Answers
I am sorry for the long wait
what is the fuel pressure key ON engine OFF and will the pressure hold or drop down fast within a second or two ?
is the fuel filter new ?
the spec is 56 - 62 key ON engine off
if the fuel filter is new you have a weak fuel pump not making enough pressure
you will need to correct the fuel pressure to spec next
the odds are with correct fuel pressure the truck will run fine
and a new fuel filter if it has not been changed yet
we have to correct that pressure first
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