hi just got a 2000 dodge 3500 with 210k miles all stock looks like a new injector pump. runs fine with no load! put a trailer maybe 4k pounds behind it tried to go up hill. 000 no power made it up but at a embarrassing 20mph. any suggestions? no gauges so i got no idea what the boost is at. I'm thinking turbo? hopefully someone has a idea. yhanks

 

Check for boost leaks. Does it smoke when loaded going up a hill? You need gauges to monitor fuel pressure, boost and EGT's.

But in stock form these trucks are pretty sluggish. Check for boost leaks and check your fuel pressure first. You don't want to burn up the VP.

 

Mine did the same and it was the turbo. Waste gate was frozen shut. Ran fine but with a load on it died out trying to climb a small grade