EVAP Two Way Valve Test

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Honda S2000, 2004 Honda S2000, 2003 Honda S2000, 2002 Honda S2000, and 2001 Honda S2000. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools Required

Vacuum/pressure gauge, 0-4 in.Hg 07JAZ-001000B
Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

Remove the fuel fill cap.
Disconnect the vapor line from the EVAP two way valve (A). Connect it to a T-fitting (B) from the vacuum gauge and a commercially available vacuum pump/gauge, 0-30 in.Hg, as shown.

Fig 1: Disconnecting Vapor Line From EVAP Two Way Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Apply vacuum slowly and continuously while watching the gauge.
The vacuum should stabilize momentarily at 0.8-2.1 kPa (0.2-0.6 in.Hg, 6-16 mmHg). If the vacuum stabilizes (valve opens) below 0.8 kPa (0.2 in.Hg, 6 mmHg) or above 2.1 kPa (0.6 in.Hg, 16 mmHg), install a new valve and retest.
Move the vacuum pump hose from the vacuum fitting to the pressure fitting, and move the vacuum gauge hose from the vacuum side to the pressure side (A) as shown.

Fig 2: Moving Vacuum Gauge Hose From Vacuum Side To Pressure Side
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Slowly pressurize the vapor line while watching the gauge. The pressure should stabilize momentarily above 1.0 kPa (0.3 in.Hg, 8 mmHg).
- If the pressure momentarily stabilizes (valve opens) above 1.0 kPa (0.3 in.Hg, 8 mmHg), the valve is OK.
- If the pressure stabilizes below 1.0 kPa (0.3 in.Hg, 8 mmHg), install a new valve and retest.