^^^ I think all the advice about checking pressures is good and proper, if you are still having operational concerns. Firstly, have you found and repaired all the leaks? When yes, then you can assess the operation of the car, and decide if you need to go further. If you had proper function before the pump change, then likely, you will afterward, if the pump is the appropriate unit for the car. You can drive yourself crazy, and broke, chasing issues with these cars, especially if you don't follow a methodology which includes realistic expectations and evaluation. Sometimes, you can be chasing something that is not a problem (how many threads have started by, "... my car is running hot at 100-105C, what do I need to do..."
How is the car running since you have the leaks repaired? Are you truly running rich, or was this diagnosis solely from the increased consumption you experienced, ie the leak(s)...
What other symptoms do you experience that indicate to you the car is running too rich? Starting issues? Smoking? Fouling plugs? Stumbling/poor power? Expect 10-12mpg around town from reports I have read on the D-Jet cars, and not much better on the highway... Can you locate a shop that can check the mixture for you by gas analysis from the exhaust? Tuners at dynos can do this, and I have seen them in action at the local "hot Rod" shops that would open their dyno up to clubs on select weekends.
Take things one step at a time, and determine if any improvement at each step...
1. Insure all leaks are repaired, then evaluate the cars operation...
2. Check the fuel pressure/delivery, affect any repairs, then evaluate...
3. Check basic tune, trigger points, plugs, etc; affect repairs indicated, then evaluate...
Good luck, and be sure to report back when you have the leaks repaired, and evaluate whether the fuel consumption issue changed any...