How to Adjust the Idle on a 1989 Honda Accord DXby Justin Moore
Over time, the idle speed may change in your Accord. This could be the result of repair work, outside temperature or the altitude at which the vehicle is driven. The normal idle speed for this vehicle is between 700 and 800 rpm (revolutions per minute). If the idle speed is too low, the vehicle will run poorly and it will become more difficult to drive. If the idle speed is too high, it could eventually cause the vehicle to run hot, and it will also lead to the waste of fuel.
Start the engine and let it warm up to normal operating temperature. Listen for the cooling fan to come on twice.
Unplug the Electronic Air Control Valve (EACV): It is located on the intake, behind the fuel rail.
Check the idle speed, with all of the car's accessories turned off. It should be around 700 to 800 rpm.
Turn the ignition off. Reconnect the EACV connector. Remove either the "clock" or "back up" fuse for 10 seconds. They are located in the fuse box, in the engine bay. This will reset the ECU.
Replace the removed fuse and start the car. Check the idle speed with the car in neutral, the fan switched on "HI" and the A/C on.
Find the idle speed adjusting screw on the throttle body. It is located at the top of the throttle body, next to a vacuum line. Rotate the screw until the proper idle speed is reached.
Place the vehicle in gear and check that the idle speed remains between 700 and 800 rpm. Check the idle speed with all accessories on (lights, radio, fan, etc.), and the A/C off. The idle should remain at 700 to 800 rpm.
- "Chilton's Honda Accord/Prelude 1984-95 Repair Manual"; Will Kessler, A.S.E., S.A.E.; 1995
- Make idle speed adjustments slowly.
- The small mark below the 1,000 rpm mark is 750 rpm. Try to get the idle speed set to this point.
Things You'll Need
- Flat-head (standard) screwdriver
- Use caution when working on a running engine.
- An engine that has been running is very hot. Be aware of where you place your hands.
Justin Moore has been writing articles professionally online since 2009. His area of expertise is in the automotive repair and maintenance field, with a focus on Japanese vehicles.