My Tremor does that when I fill it up with gas. It turns off about 3/4 of a tank. The dealer says u need to bring it in with less than half a tank so they can drop the tank and install a new part. It's been that way for over a year. I just don't fill it up.
14 mths and almost 5000 miles mostly short city drives. Almost 18mpg average. On my 21 tremor. Much better than our 10 year old grand cherokee about 12mpg average.