[Rockdaddy]

HELP, Today my 93 Grand Cherokee (4.0) had to be towed home, felt like it run out of gas and died, checked for spark and it does have it.
I Removed fuel line from injector rail and with ignition on not pumping fuel, so I dropped the gas tank and pulled the fuel pump out, but when I put 12 volts to the pump it spins up & pumps fine.
I checked for voltage at pump connector and it only gets voltage for a couple of seconds when the ignition switch is put in the on position and then goes dead. Is this normal?

[gunthagunth]

i think the pump runs to prime the lines then stops until the vehicle is started. this keeps it from flooding unless you keep clicking the key. dunno where to start on your problem tho? bad coil, not getting a strong enuf spark. gap off on plugs, clogged injectors, try some starting fluid in the throddle body

[gunthagunth]

oh yeah and check your compression

[turbinesurgeon]

I would check fuel pressure at the rail. Maybe check out the ASD relay as well. (Automatic shutdown relay) If its got fuel, ignition, and compression it should start.

[gunthagunth]

yeah the pump wouldnt turn off if the shut off switch was triggered. if you begin to turn over with starting fluid id say the problem is fuel. if theres compression, and starting fluid will not turn it over, your problem is spark. check for broken wires, spark plug wires, coil wire, have someone crank the motor in the dark with the hood slightly open so the light doesnt turn on, look for jumping spark.

[Rockdaddy]

I have comfirmed that it does have spark.
It will start up for a moment with starter fuild into thottle housing, so I do think it's a fuel deliverly issue
Where is the ASD relay located?

[mda]

if it starts with starter fluid, but will not run, then it is a fuel delevery isue.

[Rockdaddy]

I ended up replacing the Fuel Pump $$$$ and I'm back on trhe road

[gunthagunth]

glad to hear all went good