"There is NO WAY to make a diesel "run rich" other than to open the max fuel screw TOO FAR, and cause EXCESS fuelling, but all that does is to make smoke, reduce power and waste fuel. "
Thanks for your help
You may have hit the problem on the head .............
That's just the symptons I have.
Poor MPG,
lack of power = reduced top speed.
Smokes (expecially when cold, it always seems as if it's overchoking
Matter of interest where (approx) is the fuel screw? I vaguely remember the guy pointing somewhere to the offside of the engine that the adjuster was there.
I don't want to mess, just interested.
On the injection pump somewhere.
Depends on which engine and which pump.
However, it will probably be under the turbo boost controller.
You could have that off and CLEAN it. Easy-peasy job.
4 small screws and then just gently clean the thing.
If it happens to be stuck in the BOOST position, then that could be your problem.
Send a photo looking down on your injection pump.
CharlesY