High Fuel Consumption - help pleaase

Hi
I need some advise if possible. I have a weird situation with my freelander 99, 1.8 Petrol. Since last 2 yrs, been trying to fix my freelander. Changed engine after several HGF, many more parts including a faulty ECU. Since then, had a very high fuel consumption, replaced the lamda sensor, injectors, coolant sensor, etc, everything that I have read about on this forum. Nothing worked. Recently my radiator fan stop working, found out that the relay is faulty. By mistake, forgot to turn the aircon off after testing it and noticed that my fuel consumption is back to normal when the aircon is on (aircon does not actually work though, just normal air)!! I currently disconnected the coolant sensor so the radiator fan is always on as here, in Mauritius, we are in full summer so temp always near half way on gauge! Does this make any sense about the fuel consumption? as always thought aircon should consume more fuel and not less! any link between the disconnected coolant sensor, a faulty relay , aircon and fuel consumption? How can this be explained pleasee?

just out of interest, what do you call high fuel consumption?
what is your mph, urban? motorway? off road? mixed?

+1

yu really need to get yourself a diagnostic kit - as yu are so far from support.

http://www.landyzone.co.uk/lz/f9/self-test-mode-freelander-1-diagnostics-124575.html

It was doing about 13-15 mpg in urban for last 2 yrs. Today left the aircon on, with the coolant sensor unplugged, it seems back to normal after a very long time, looks like 28 mpg. Gas quite expensive here, about 1.2 pounds per litre! So any idea what's going on please? As normally, aircon should consume more and even more with the coolant sensor unplugged! Tomorrow going to have a diagnotic done, so any advise what should we look for?