Ok, 1st question - fuel pressure - checked pressure and it holds at 31-32 while running, when you shut engine off it drops to 0 is this the regulator or pump? 2nd question - motor runs great! but at no specific time while driving it acts like it just runs out of gas and it may start back or it may not - could this be same problem? has had a new tune up and new coil replaced. 1993 jeep cherokee sport 4.0 HO motor. Thanks for the help!

 

I would replace the Throttle position sensor first!! Im no fuel pressure professional but if the XJ isnt running, in my mind there shouldnt be any pressure as the fuel pump is not running.... I would also say your second question very well could be fixed by my idea...the TPS. Good Luck!!

 

Isn't 93 the first year you might get something with the key trick?

 

The factory service manual will outline an "acceptable" amount of fuel pressure drop in a certain amount of time after you turn the key OFF. But an immediate drop to zero indicates that you have a large "leakdown" issue somewhere in the fuel line. Most likely the check valve for the fuel pump.

As for the other issue of the vehicle dying, this may not be related to the other one. It is possible that you are on the front end of a crankshaft position sensor failing. They often give you these symptoms when they are starting to flake out. SEARCH for lots of threads on the crank sensor.