You have a vacuum leak. That's what causes high idle.
Find a way to stop the fan when the engine is running. I get a pair of vice-grips and clip it to the fan shroud when the engine is NOT cranked, then crank the engine. The fan clutch will let it slip for a while.
Now get something extremely flammable like Starter Fluid, and squirt short bursts around the engine hoses. If there is a leak in one of the lines, the Starter Fluid will suck into the hole and the engine will idle will speed up. If nothing happens, wait for the Starter Fluid to evaporate before moving to another location.
Note: It might be a good idea to keep a fire extinguisher handy during this because Starter Fluid is so volatile. If it catches on fire, the engine will burn up. I'm a "know it all", so I never have used a fire extinguisher. One day, I'll be sorry.
Once you have found the vacuum leak, turn the engine off, remove the vice grips, and go replace that vacuum hose.
Find a way to stop the fan when the engine is running. I get a pair of vice-grips and clip it to the fan shroud when the engine is NOT cranked, then crank the engine. The fan clutch will let it slip for a while.
Now get something extremely flammable like Starter Fluid, and squirt short bursts around the engine hoses. If there is a leak in one of the lines, the Starter Fluid will suck into the hole and the engine will idle will speed up. If nothing happens, wait for the Starter Fluid to evaporate before moving to another location.
Note: It might be a good idea to keep a fire extinguisher handy during this because Starter Fluid is so volatile. If it catches on fire, the engine will burn up. I'm a "know it all", so I never have used a fire extinguisher. One day, I'll be sorry.
Once you have found the vacuum leak, turn the engine off, remove the vice grips, and go replace that vacuum hose.