Toyota Repair: 1992 4runner with a 3.0 idles at 1500rpm, vacuum hose, adjustment screw

Question
i have a 92 4runner and it alwise idles at 1500rpms. it does not affect the driving at all. i was just woundering if any one might know what could be causing this????

Answer
This engine has adjustable idle, there is an adjustment screw on the throttle body towards the front of the engine, try moving this adjuster and see if the engine responds, if not make sure the throttle cable is not adjusted too thight which will keep the throttle plate from closing, there is also a throttle opener that opens the throttle a small amount with the engine off, there is a vacuum hose attached to it, when the engine runs vacuum is applied to the diaphragm to close the throttle plate all the way, you can verify it's operation by disconnecting the vacuum hose, the rpm should go up but if the unit is leaking or there is no vacuum it will idle to fast all the time, this can also be checked by removing the intake hose from the throttle body and applying vacuum with a pump to the throttle opener to see if the plate closes all the way.