1993 Toyota Corona terrible fuel consumption/smoky
Hi! I use a 1994 Toyota Corona as my daily commute. It has a 3S-FE 2.0 liter engine So far it has logged 275K kms without much issues. Recently I had the engine overhauled and replaced the following; Timing belt, tensioner bearings, con rod bearings, piston rings, In/Ex valves, valve seals, water pump, and spark plugs and all seals and gaskets. However when it was completed, I noticed that black smoke is being emitted from the exhaust pipe and the fuel consumption was so terrible. I had the spark plugs inspected and they were covered with soot indicating the presence of unburned or excess fuel. I already had the coil replaced and still emits black smoke. Also I tried inspecting the fuel rail regulator but it seems to be in order. No CHECK ENGINE signal encountered. What did the mechanic miss here? Please help?