Felicia 1.9D fuel system

How to check the diesel injector pump timing?

When fitting a new cam belt recently, I used the crankshaft mark ( bell housing inpection hole), the cam holding tool (with equal feeler gauges each side to take out any slack) and injection pump locating pin.

Are there any other checks that I can do to verify that the injection system is set up for maximum fuel economy?

Many Thanks,

Sea Kayaker

Edit: Before, and after Cam Belt change, I get 55mpg on long runs, but want to improve on that figure.