I have a 2003 F-250 Turbo Diesel 6.0 with 110,000 miles. Recently, my truck has started to cut off when making sharp right hand turns. The problem is more likely to occur when applying gas. At slower turns, the fuel-separator light will come on and the engine will begin to stall, but it will not completely stall. Similarly, when I cross the train tracks, the fuel separator light will come on and the engine will begin to stall, but it will not completely stall.

The fuel level does not seem to affect the frequency or severity. The problem will occur when the tank is 3/4 full or nearly empty.

The dealer determined that I needed a new fuel pump. A new pump was installed; however, at the first severe turn, the fuel separator light came on and the truck nearly stalled.

Any guidance that I could provide to the mechanic would be appreciated.

Thanks,
Harold Duvall