I saw this a little late. Yay - I guessed fuel!
Z-Convert is right, happened to me too. A fuse was bad. Once it died on me (at work) I checked the fuel first, by dumping in 2 gallons. Fired right up, so I checked and found a bad fuse.
I don't know what your buddy's car has power running off of....did you guys figure out whats wrong w/ his gauge?