After warmup engine stays at 1500 rpm on 1991 Acura Legend

alway's idle at 1500 rpm

Asked by for the 1991 Acura Legend
Could be a vacuum leak or an idle air control motor problem. I forget if that engine like some Accords uses a waxstat element that assists in raising the idle speed when the engine is cold as the engine warms up the element heats up and slows down the idle. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate