Loss of power and white smoke
#1
#2
Check for leaks, it's some how cutting fuel pressure wheather you overflow valve is failing, lift pump is failing, leaking in air, loose line somewhere. Check all that. If you have money and time/mechanical skill Id just upgrade the fuel system to a fass and put in a tork tek ofv. While you do that you can check the whole system. And basically the only thing not new is the engine side. Fuel systems are riddled with possibilities to failure due to age. Just my 2 cents. If you find nothing wrong with your supply to the pump and no leaks you may be looking at bad injectors or pump.
#3