ob1-w4n

Hi Guys, Its my first post here. I recently bought a FB-15 (YOM 2002 with the new shell) Auto transmission. After I bought it I drove it a couple hundred KM within colombo with oct 95 fuel and it did around 10.5 KmPL. But there was a problem, the engine would not start if I don't give some throttle when i turn the key. So I took it to A*W they changed the injectors and replaced the fuel filter and plugs and tuned the engine. I also changed all 4 tires. After that i went outstation (rathnapura and awissawella) when i came back i noticed not the car only does around 9.5 KMPL even outstations. I am clueless as to why this happened, when I called A*W they said to bring it back to test. I am a bit reluctant to go them unless I must because they tend to rip you off. Please advice. Regards