1994 Acura Legend I smell unburnt fuel

Engine Performance problem
1994 Acura Legend 4 cyl Front Wheel Drive Automatic 172xxx miles

My 1994 integra smells like un burnt fuel, my friend said that my engine is burning fuel really rich, we checked the iac, it was clogged so we cleaned it, we check the spark plugs, it was used up so I changed it, also changed the valve cover. But I still smell un burnt fuel/gas, whats the cause?