Honda Prelude B20A EACV Service

EACV- Electronic Air Control Valve

Its purpose is to control amount of air when there is load such as 

alternator, steering, compressor or when the engine is cold.

EACV is controlled by ECU.

Loosen up fuel injector wiring cover bolts sized 10.

Need to modify the wrench to loosen one of the EACV bolt.
I had try coupling or socket.
They were no suitable as the fuel rail prevented them to fit  the bolt.
Other way is to take out the fuel rail...lots of work.


Now it fits.

Previous owner or technician put silicone gasket.
Very ugly since the excessive silicone cover the holes.
Actually you can put if you cant find the "8" rubber but must be very thin.

Tested the EACV. 

You should hear 'click' sound.

Clean the holes at the intake.

New "8" rubber gasket

I put some heavy grease.

It helps the EACV fit evenly.

Also heavy grease.

1. Put everything back as normal
2. Start engine.
3. Unplug EACV connector when engine already warmed up.
4. Adjust IDLE screw
5. Reset ECU
6. Test Drive.

Good Luck.