change the oil, makes all the difference in the world, then air filter and fill'er up with hi-test gasoline. this actually worked for my just by changing the oil and burning premium gas. so that should be definite if it was running rich.

you might or might not want to check for a vacuum leak with a can of "starting fluid" (dimethyl ether), but that can be bad if you got a faulty ignition wires or loose battery connection i just hold the can back and wear glasses, the stuffs more volatile than anything but has no btu's just burns off "woooosh"

spray it around hoses, intake gaskets, injectors, wear glasses. if engine rpm increase, duh leak.