Your question: "My 2009 LR 3 was running fine, I went into Walmart, came out, it will turn over try to start and changes tone and just turns over and won't start. It did this before and I let it sit over night and it started right up."

 

I do not have an answer for you myself but I can suggest that you post your threads in the appropriate section of this forum, doing so will increase the odds of somebody being able to find your post and help you through your situation. You have a LR3 so post any technical/need help questions in this section: LR3 - Land Rover Forums - Land Rover Enthusiast Forum

on a side note if you have a 2009 LR3 then might it still be covered by a warranty?

 

Could be the crank shaft position sensor.

The LR3 has a crank shaft position sensor, similar to the D1 and D2. When this sensor begins to fail, it does so when engine block is hot, like after driving and parking for a short period. Will crank, but no spark to plugs. After it cools off, or if you pour cold water on it, it starts working again and truck will start.

Attached pages from LR3 shop manual so you can find sensor.