I have a 1997 XJ with a 4.0. For some reason it always takes forever to start. Some days it takes up to 8ish seconds to start. If I hold down on the gas, it will start a little quicker. And for some reason it always stalls at a stop sign about 2 miles from my house it's on flat ground and I stop at 3 or 4 other stop signs before it and it never stalls. Sometimes it stalls when I'm at a fairly steep angle at idle too. I'm at the beach for a while so I cant check my fuel pressure until I get home and borrow a checker. Could it be my fuel pump? I've tried "new" junkyard injectors and it didnt do anything.

 

Does the long start happen every time you start? Or only after you have been driving it and turn it off to go into the store or after its sat a while? Search around, there are a number of things that can cause that.

Idle Air Control
Crank Position Sensor
Cap Rotor
Plugs
Wires
Fuel Pump You can borrow a pressure gauge from most auto parts stores.
Fuel Filter

Good luck. Post your progress.
There are tutorials on how to test the different components. Try that rather than just throwing parts at it. The fuel filter is cheap. Try replacing that. you can try blowing through the old filter to see if it was clogged.

 

I forgot to add this into the post: if it has ran in the past half hour then it starts up no problem. And if I turn the key a few times before starting it, it sometimes starts easier. So I think it might be a fuel issue