Originally Posted by
isuzurover
Apart from the low top speed, what does it drive/accelerate like, and how much does it smoke (and what colour).
I would suspect timing as a first port of call. If you have dribbly injectors it would likely be smoky. New nozzles are very cheap. The pump could be at fault, but I have never reuilt mine, just replaced a couple of seals. So my pump is probaly far below optimal, but I can still reach the speed shown above (or could when the engine was healthy!).
A good 2.25D should accelerate almost as quickly as a 2.25P.
If you have the vacuum assembly on the intake, removing it will gain you power.
If the throttle stop (top speed) is set incorrectly, it should still accelerate well.
We bought 6 packets of disposable ear plugs before the trip from Brisbane-Perth :D
I normally sat on 50-55 mph though - both for the sake of the engine, and my (earplugged) ears!!!