engine just quits but will restart after a time. will only run for 10-15 minutes on 1999 Dodge Ram 2500

Put two new injection pumps in and two lift pumps last year the lates in Sept. 2011. Have checked fuel lines, changed fuel cap, bled fuel filter, I'm out of ideas. there is no codes on scanner or engine light.

Asked by for the 1999 Dodge Ram 2500