Need help with my Jeep!!!

Hey all,
I drive a Jeep Cherokee sport '99. I bought a new battery for it last october, about a year ago. Last night I accidently left the interior lights on, and this morning I "surprisingly" found my car dead. Myself and a friend attempted to jump it but to no avail, the engine wouldn't even turn over. We let the batter charge for about an hour randomly trying to start it up again. While the engine did start to try and turn over it still wouldn't start, but it felt like it got closer every time. Now, the battery is fully charged but it still won't start. If you turn the ignition and hit the gas it will start but immediately stop when you take your foot off the gas. Any help here? IT would be appreciated, thanks!
-Purdy

Automatic transmission if that helps, about 110k miles.

Did you check any of the fuses yet? Look for fuel pump, ignition, and automatic shutdown systems. Check the fuses first. Try the PDC (power distribution center) first (under hood passenger side--LH drive vehicle).

Yea we've checked those too, got it running this morning, if you hold down the gas peddle very slightly it'll start up and run but it will either stall out or just turn off after a little while.
I take it offroading quite a bit, but it's never had any problems before. Do you think it could be related?

I don't think off roading per se is the problem, except...do you wash it down when you have a lot of dirt in there?

After I get done with a couple of trail runs, I usually clean out the engine compartment and replace the air filter. Of course, make sure it gets dried out properly afterwards.

Why don't you start by taking the air filter out, then clean and check the throttle body plate (clean and check gap). Look at the TPS (throttle position sensor) and test with a voltmeter if possible. Then take out the spark plugs and check for wear. I alway use Champion spark plugs in the 4.0L...they seem to work the best according to experienced Jeep techs.

disconnect battery for awhile to allow chance for computer chip to reset itself. rehook up battery and see if this has helped to resolve problem.

Something has changed because of battery going dead from lites being left on. You say u were ok before this happened. I,m thinking chip memory
has got disturbed.

This is just a idea not a fix.