Loses power on hills

[abadboy]

I have a 1982 Southwind motorhome with a 6.2L and a 3 speed automatic tranny w/o overdrive, 70000 miles, rebuilt injector pump 10000 miles ago. Returning from a trip last weekend as I was halfway up a mountain passes the engine suddenly lost power. It felt like it was running out of fuel. I made it over the pass by feathering the foot feed and keeping it right at 40 mph. If I pushed the pedal or shifted to 2nd it would bog down again. When I went over the top it ran fine going downhill and on the flat. When I got off the mountain I changed both fuel filters. Going up the next pass the same thing happened. I bypassed the next pass and was about 5 miles from home on the flat when it happened again this time blowing a little white smoke until I let up on the foot feed. I coasted a little way and everything return to normal. Does anybody have any idea whats going on?

[Robyn]

A couple things come to mind. Fuel delivery issues with the mechanical pump down on the side of the engine.

Tank sock possibly plugged or you may have an air leak between the tank and the IP.
With the engine idleing you should have positive pressure to the fuel filter from the lift pump if not therein lies the issue.
If the lift pump is a high miler it sure would pay to change it.
Make sure you can get good fuel flow from the tank and that your return line is free too all the way from the IP.
Check the return line from the IP by replacing it with a clear plastic line (Temporary) and run the engine and make sure you have fuel flowing and NO AIR.
Let us know

Robyn