I have a 1999 Jeep Grand Cherokee Limited 4.0l v6, that stalls while cruising down the road, and doesn't just start right back up, takes it awhile. Hesitation and jerking during acceleration (changed the spark plugs) Still does it right before it stalls. After I changed the spark plugs and it still proceeded to be a pain in the rear, I decided to hook it up to see what codes it would throw... Low and behold it doesn't throw off any code what so ever!!! I'm at a loss. I know there is obviously something wrong with it but without codes it like playing a guessing game that I can't afford.

SOURCE: 2001 Jeep Grand Cherokee code P1391

I would check to be sure that the timing chain hasn't jumped at all ..

SOURCE: hesitation during acceleration

could be the type of plug you are using.I was told only to use ngk plugs.I recently put bosch plugs in my mazda 3 and the check engine light came on and it started missfiring.

SOURCE: Jeep Grand Cherokee Limited P0700 diagnostic problem

P0700 means there is a transmission fault code in the transmission controller. Since the transmission controller doesn't have a light attached, it tells the engine controller to turn the light on using this code. You'll have to access the transmission controller to further diagnose the problem.

SOURCE: Hesitation during aceleration

You may have a vaccume leak

SOURCE: Changing spark plug wires on 2001 Jeep Grand cherokee

yah direct ignition coil pack does away for the need a a distributer cap and rotor.much higher energy ignition system where the computer tell when to fire.if that helps.not hard to change.as long as you change them one at a time so you don't screw up the order.