Air Pump & Relief Valve
- Disconnect air pump-to-check valve hose at valve and plug the hose. Disconnect return hose from air cleaner and install a pressure gauge in hose. See Fig 1.
- Start and idle engine and check pressure gauge. No pressure should be indicated on gauge. If pressure is indicated, see TROUBLE SHOOTING in this article.
- Raise engine speed to 3500 RPM and disconnect vacuum tube leading from delay valve to the intake manifold at the manifold. Within 2-10 seconds (4-20 seconds on auto, trans, equipped models), more than 5.9 psi (0.4 kg/cm2
) should be indicated on pressure gauge.
- Allow engine to return to idle. If pressure or time is not as specified in preceding step, see TROUBLE SHOOTING in this article.
- Gradually increase engine speed and make sure that air begins to exhaust from air by-pass relief valve at a pressure of 2.2-5.9 psi (0.15-0.4 kg/cm2
).
- If pressure is not within specifications when air begins to exhaust, replace the air by-pass valve assembly. Reconnect hose to intake manifold and continue with choke switch test.
Courtesy of AMERICAN HONDA MOTOR CO., INC.