An easy way to test for a leakdown problem without tools is to "cycle" the key when cold starting.
Have your friend turn the key to the on position (not all the way to start). Wait a couple of seconds, then turn the key back to off. Do that 3 or 4 times then go ahead and start it. If the jeep then starts right up, he probably has a leakdown issue.
When the key is turned to the on position, the fuel pump activates for 2 seconds, pressurizing the fuel lines. Once a leakdown condition is diagnosed, it needs to be narrowed down between 3 possibilities: leak in the fuel line somewhere, leaky check valve in the fuel pump assembly, or one or more leaky fuel injectors. The way to do this is with a fuel pressure tester.
I ended up replacing the fuel pump assembly in my 2000 with the same symptoms.