the books are free, to read on this car. ask.
is this the 4.0L ? I-6?
all jeeps 1993 to now have a feature called ASD relay
and all stall every 3 seconds. (or at anytime !)
if one of 8 failures happen.
the first step is to scan it, on dead engine,, or stalling engine
the PCM tells you why it dropped the ASD, the 7- 8 reasons.
lacking that simple tool, you get to do this the long hard way.
is that you>? (no judgement but not one poster here wants to use tools, it seems)
so read this page.
most of the failures can not be tested with a $10 voltmeter.
if you scan it, it will tell you.
now the pump, if the ASD drops the pump does not get 12vdc power.
if fact the PCm will even test the pump relay as it turns it on
oops the relay was commanded on but the relay output is dead.
if you measure ground at the pump with the meter black lead at battery minus and red to pump ground
and the volts is 0v all time time?, cranking then the ground is NOT bad. (earth) (for sure) but the hot line, that is a CONTROLLED line so car will not crash then burn... regs. by law.
if the 12vdc is dead to pump cranking, the relay is bad! (can be)
or the PCM is cutting it on PURPOSE> , as all EFI systems do.
that is why we have scan tools to see WHY..