Power Valve
NOTE:
The power valve opens as vacuum is reduced and supplies supplementary fuel into main fuel passage when vehicle is in power mode (under acceleration).
- Disconnect vacuum hose from power valve. Connect a hand vacuum pump to the valve and draw vacuum. Vacuum should remain steady. If vacuum decreases, replace diaphragm and retest.
- If vacuum is steady, start engine and warm to operating temperature. Disconnect vacuum hose from power valve and connect vacuum gauge to hose. Vacuum should be available. If vacuum is available, go to step 6).
- If vacuum is not available, check for voltage at power valve control solenoid valve, in emission control box. If there is voltage, check control unit.
- If there is no voltage, disconnect hose at check valve inlet side (hose No. 20) and check for vacuum. See Fig 1 . If there is vacuum, check check valve operation.
- If check valve operation is OK, replace power valve control solenoid valve and retest. If there is no vacuum, check all vacuum lines for disconnected hose, leaks or blockage.
- Ground the control unit wire (Red). Check for vacuum to power valve (hose No. 14). See Fig 1 . Vacuum should disappear. If vacuum disappears, system is OK. Reconnect vacuum hose. Test is complete.
- If vacuum does not disappear, check for voltage at power valve control solenoid valve in emission control box. If there is no voltage, check control unit. If there is voltage, replace power valve control solenoid valve and retest.