Bro if your Liana is using so much fuel, there is definitely a leak somewhere. Have the whole fuel system carefully inspected for leaks including the fuel tank, pump and fuel lines.
Shims are "tikkiaan" in local language and are the equivalent of tappets in other engines. Its the same kind of tikkiaan in diesel engines. Having those adjusted is very important and your fuel consumption, pick up and engine's health depend on it. Get it done from a reputed dealership. Pindi members will be able to help you better
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