1500 Models
- Ensure engine coolant is below 122°F (50°C). Attach a vacuum gauge to the inner port of thermovalve C. Check for vacuum at idle speed. If vacuum is present, go to step 3). If not, check for vacuum at outer port.
- If no vacuum, check vacuum line to auxiliary intake port for leaks and/or blockage. If okay, replace cranking solenoid valve. If vacuum is found at outer port, replace thermovalve C.
- Stop engine. Remove the secondary coil wire from distributor cap and ground it. Turn ignition key to start position and check for vacuum. If vacuum is present, replace cranking solenoid valve.
- Warm the engine to operating temperature. Check for vacuum at thermovalve C. If vacuum is present at idle speed, replace thermovalve C.
- Remove air cleaner cover and filter. Start engine and run at idle speed. Check for bubbling noise from air suction port. See Fig 1 . If bubbling noise is heard, proceed to step 9).
- If bubbling noise is not heard, disconnect hose number 5 from air suction cut-off diaphragm and check for vacuum. If vacuum is present, replace air suction cut-off diaphragm and retest. If no vacuum is present, reconnect hose disconnected in step 5).
- Disconnect hose number 32 from control box at vacuum hose manifold and check for vacuum at vacuum hose manifold. If no vacuum is present, check vacuum. If okay, replace air bleed valve B and retest.
- If vacuum is present, check for voltage at air suction control valve (Green/Red) in box number 1. If no voltage, go to Trouble Shooting. If voltage is present, replace air suction control valve and retest.
- Raise engine speed above 3500 RPM. If a bubbling noise is not heard, system is okay. If bubbling noise is heard, check for voltage at air suction control solenoid valve (Green/Red wire) in box number 1.
- If there is voltage, go to Trouble Shooting. If there is no voltage, replace the air suction control valve and retest.
- Heat air bleed valve to 140°F (60°C). Ensure bubbling noise stops. If not, replace air bleed valve.