For years I experienced my D90 loosing power while driving. Didn't matter what the speed or temperature. I would turn off the ignition, then restart and the truck would run just fine. I replaced everything I could think of to solve the issue, new coil etc. Finally I took out all fuses, they were fine. Cleaned the fuses with a wire brush. Saturated the fuse box with a spray dielectric and haven't had an issue of stalling since. 25 years to figure that one out.

 

when you say "loss of power" do you mean electrical power or engine power ?