Civic with engine swap HELP! minor problem!?

i have a 91 civ h/b with a vtec d16z6 just put in. its great job done, except it runs VERY rich you can always smell gas while parked and driving you can smell somtimes. and makes it bad on gas mileage!it seems powerful but im sure it sould be more powerful. it also idles up and down from like 800/1000 rpm to 1200/1300rpm all the time. every second idles up and down. i was thinking maybe a va problem, or timing belt even tho its newer, or most likely a wireing problem i think. it has the ECU for the engine and a new wireharness maybe aftermarket. help please. i need detailed advice.