Accord 1985-89 and Prelude 1986-89
The fast idle valve is set at the factory and should not be reset. Check the piping of the positive crankcase ventilation system for kinks, disconnections, blockages, etc. Check the tightness of the throttle valves.
Idle speed too high after warming up the engine
1. Make sure the engine is well warmed up.
2. Check that the idle control function is not impaired.
3. Remove the fast idle valve cover.
4. Check the tightness of the valve - if it does not close tightly, you can feel the air flow at the valve location. This is checked by applying a finger to the location of the valve.
5. If you hear any whistle, then the valve is leaking in this place. Replace fast idle valve and adjust idle speed.
Idle speed too low after warming up the engine
1. Remove the idle adjustment screw.
2. Clean the idle adjustment screw and bypass with a carburetor cleaner.
3. Adjust idle speed after cleaning.
Speed x.x. low on a cold engine.
The fast idle speed should be 1000-1800 rpm.
1. Remove the fast idle valve assembly from the throttle.
2. Cool the wax part of the fast idle valve with cold water to 5-30°C.
3. Blow the fast idle valve through part A. Check that a strong air flow can pass through it without much resistance.
4. If the air does not pass or passes with difficulty - replace the valve and adjust the idle speed.