2004 Jeep Grand Cherokee 4.0 acts like it jumped time

2006 chev SUV parking light will turn off and run Battier down

2006 chev SUV lights

With that many miles, I too would suspect the timing chain jumped timing. With no codes it's hard to say. Starter fluid test indicates that fuel delivery is not the problem. A common ignition failure of this engine is the crankshaft position sensor, code P0320. It's located midway up on the bell housing, driver's side. They will sometimes cool off and start running again, but when they fail, there will be no spark for a while.

Thank You. I think it had no codes because the battery was out for so long and I didnt crank it long enough to give a code. I'll try that later today and see what I find out. If I still can't get it to throw a code, I'll change the crank sensor like you said, and I've also heard of a cam sensor causing this, so I'll change that too, they're only about 15 bucks a piece for cheap brand ones. I've changed them on other Jeeps before, but they just simply did not fire at all. I've heard that on these 4.0 straight 6's, they have a timing chain and they hardly ever break or wear out, and it looks like a bear to change

You are correct about the codes were lost while battery was out. I might add, when a crankshaft position sensor starts to fail, the driver will notice that the tachometer hand will drop to zero suddenly and then bounce back up. That's because that sensor provides signal for the tachometer reading. Camshaft sensor is a lot easier to replace and it too provides spark and maybe injector signal. Good Luck

I did notice the tach doing that, but I figured it was because the battery was extremely low.

Tachometer needle dropping suddenly and bouncing back up is a sure sign the crank shaft position sensor is cutting off spark and signal to the tachometer. I "counts" the rotation of the flywheel....RPMs.