Hi there, I have a stock 1999 Dodge diesel. My problem is I pull a 21 foot fifth wheel and a 17 foot ski boat behind that when going to the lake. All low end power and torque is fine it's when I'm going 65 and 70 in overdrive, there is no top end power. Mainly it's when going up hills or when the AC is on or both. If I really mash down on the pedal it will shift (automatic) down but it doesn't make much gains to speed up but just holds steady until I get to the top of the hill. My question being can anyone suggets an aftermarket add on to help out with this probelm, maybe one of those power pucks or something like that.

 

I bet the fuel lift pump has died. Better get it checked before the injection pump goes too! It will still run with no pressure. Has it been checked?