TX5 94 V6 Fuel Consumption

Hi,
I have a telstar tx5, but as of late the fuel conumption has gotton really bad quickly. I have not noticed any loss in performance. Used to get abou 10km/l, but now its not even close. The fuelpump and sparkplugs has been replaced recently, and I also had the injectors cleaned. Has anyone got any idea why it would suddenly use a lot more fuel than it should?