I did a search and could not fine this exact problem. I have a 99 with a 4.0 and a standard trans. and 235k. Starts fine when warm or after running for 15 seconds. Have a brand new battery but when I hook up the booster and spin it extra fast it starts after about 10 seconds. Starter fluid has no effect so don't think it's a fuel problem. Once started it will start instantly until the next morning.

 

Ended up being crank position sensor, go figure.