arvy,

I was in the same situation, Newly overhauled but noticed bad idle and high fuel consumption. Yung connection ng vacuum to the MAP sensor was broken by the mechanics alalay at tinapalan lang ng epoxy. Kaya mausok pa din.

I suggest you take out the plugs and observe fuel consumption. Pag maitim yung tips, something is wrong with the fuel air mixture. Patroubleshoot mo din yung vacuum system at menor mo.

Im not sure kung recommended to ng iba, but I also put water into the tailpipe and let is soak a few minutes. Turn on the engine and youll see that carbon deposits are expelled. This helps clear up the deposits from the tailpipe which could make your exhaust smoke black.