Fuel Injected Engines

1986-87 Civic & CRX

1. Disconnect ported vacuum (lower) hose from purge control valve and connect vacuum gauge to hose.
2. Start engine and accelerate briefly while noting gauge reading. Do not allow engine to run long enough to warm coolant.
3. If vacuum is indicated with engine running at idle, check for improper throttle adjustment or incorrect vacuum hose routing. If no vacuum is indicated when engine is accelerated, inspect vacuum system and repair as needed.
4. Ensure coolant temperature is below 149°F.
5. Disconnect manifold vacuum signal (upper) hose from purge control diaphragm valve and connect vacuum gauge to hose.
6. Start engine and allow to idle. Vacuum should not be present.
7. If vacuum is not present, disconnect vacuum gauge and reconnect hose. If vacuum is present, check purge cut-off solenoid valve for proper operation and inspect solenoid control wiring.
8. Run engine until it reaches normal operating temperature. Vacuum should be present.
9. If vacuum is not present, inspect vacuum hoses for leaks and blockage and repair as needed.
10. If vacuum system is satisfactory, check purge cut-off solenoid valve for proper operation and inspect solenoid control wiring.
11. If vacuum readings are not as specified and all other components are satisfactory, substitute known good emission system control unit and repeat tests.