offroad420

I turn the ignition and the fuel pressure gose to 50 psi but it looses pressure fairly fast within 4 second. It back be down to zero. Seems like it's going some where's. Fuel pressure regulators has bin change. It's hard to start sometimes. Sometime easy. Just need it fix befor winter. Runs great when turned on. Fuel pump works great. Plz help

notop46

Could be an injector leaking. Try starting, stopping, waiting. Repeat 3-4 times. Pull plugs and see if one of them is dark or smells like gas. If yes, then that injector is leaking.

DFlintstone

How about this test to differentiate between a leaking injector and the check valve in the fuel pump. Turn it on and off a bunch of times, enough to flood a cylinder with a leaking injector. Then start it and see if it misses a bit at first.
Just a thought, maybe a pointless waste of time.

tjwalker

Always post year/engine. There are significant differences in the fuel delivery system through the years.

notop46

After starting, only run for a few seconds before stopping, waiting 10 seconds, and repeating sequence

I was worried that he could flood and hydrolock the cylinder. If he starts it for a few seconds, it will be rich, but burn most of the the fuel off.

On a cold engine with all the injector clips properly installed and with a friend holding a good fire extinquisher ready to rock, you could pull the fuel rail and cycle the ignition to run (NOT START) and look for the leaking injector. This could be dangerous and should only be performed by trained proffesionals in a controled, out-doors environment

volaredon

probably the regulator/filter on top of the fuel pump module; contrary to what the parts stores claim it IS replaceable seperately. Look on Ebay under "jeep fuel regulator"; NOTE; the $35 ones are the ESACT SAME one s as the $169 ones.
I have replaced a few of tehse. even if you do this + a (seperately replaceable) pump its cheaper than buying the whole assembly;; buying a whole assembly makes no sense unless the gas gauge is dead.
other than the screen at the bottom of the pump inside the tank this silver can is your only fuel filter on there.

I have seen this filter regulator cause this issue more times than I care to remember; long crank times anybody> cuz you gotta grind on teh starter til pressure comes back on the fuel line.

offroad420

Thnx for advise. I started the jeep up this morning and seen gas come out from the top of the gas tank.

DFlintstone

Great! Maybe just a loose connection/fuel line.