So I let my 2002 Disco II sit for about a week while I was out of town. When I got back, the battery was dead, so I jumped it off with a jump box and it turned over normally. As soon as it cranked, the engine revved like the gas pedal was to the floor. I instantly cut it off and tried it again shortly there after and it did the same thing. Anyone know where to start looking? Obviously there are no codes to check since the battery was dead. Any advice would be appreciated, thanks!

 

Check your throttle body - one of the wires may be stuck.

 

What he said. And check to make sure it moves freely, it may be starting to be seized up and not having moved for a while may let it get stuck (you may have touched the gas pedal and it didn't return)

 

Was there not a member here that had that issue here about 1-2 months ago and posted a video. They may help you if they found the problem