Fisherman:

There is not one thing wrong with your IP. Do not mess about with it!

What you need to do is reduce the max fuel delivery at high altitude or put up with the smoke!

I'm not sure where the adjustment is (on the pump, I think, a screw with a lock nut) -- this determines the maximum travel of the fuel delivery control rack. You are overfueling at high altitude because the air is less dense, not because there is anything wrong with the pump. You will get lower power at sea level, but that may be preferable to huge clouds of inky smoke!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!