ford laser 2000 fuel consumption problem

[dasun1993]

i have ford laser 2000 (bj5p) which i brought few month ago. from the day i took this vehicle its fuel consumption is around 5 -6 kmpl. then i did a full tune up from sumudu automobiles, but problem was not solved . then my mechanic (sumudu automible) say that there were oil sluges inside my engine (some stranger noise also came) so he open the upper cover and then he says he need to open the head also. after that he says engine bor and pistons are also not in a good condition , then we replace engine "mottayak". but my problem is remain same. still fuel consumption is 5-6 kmpl. please help me this is my first car

note-  previous owner has bypass the alternator cable from ECU for some reason 

[mash1981]

Usual fuel consumption for a bj is like 8kmpl in the city.your one is too low.as of tune up what did your mechanic do?did he replace the spark plugs,cleaning the throttle body,IAC valve,injectors,fuel filter,air filter?

Whats the milage of the car?.i think engine rebuilt would have been your second choice.a proper tune up would have been done.

by the way.Why dont you refer the car to some mazda expert.