NissanDiesel Forums

I just bought a ud 1200. It seems to lack power. It struggles to hold 55mph up hills on the highway empty. It is a manual with a 5 speed. Is it normal for these motors to be so lacking in horsepower? What should I start with looking at? The air filter is clean. The rubber tube leading to the turbo, from the air cleaner, seems a bit squishy. The only line that seems questionable is a little rubber line from the front of the turbo that leads to a diaphragm valve of some sort. Its old and dry rotted. Is there way to safely turn the power up on these things? I pulled the exhaust off from the exhaust brake thinking i could give it a little more ease at breathing. That seemed to help.

details:
XNDXHO4.6FAB
FD46TA-U2
4.617l
6 cylinder diesel
Nissan UD 1200 with a flatbed

You say the line from the air cleaner to the turbo is a bit "squishy". Is there a chance this is flattening out under load and restricting the air from entering the turbo ?

Took it to a shop and the boost was low. They cleaned and adjusted the turbo. Runs as good as it will get. Better fuel mileage and a noticeable difference in power. They informed me there is not a lot you can do with this engine.