I have a 1987 bronco 2 with a 2.9 liter fuel injected engine. It runs great on the highway but when I drive for 5- 10 minutes on bumpy roads it suddenly losses power and dies. If I wait 15-30 minutes it will restart and run great again as long as I get back to a paved road. I’ve replace the fuel filter and in-line fuel pump. Not sure what to do next. Bought to to 4x4 out in the desert so need it to go slow on bumpy roads.