Cold Engine
- Disconnect the air suction lower hose at the anti-afterburn valve. Start the engine and quickly raise the engine speed to 2500 RPM and close the throttle suddenly. If there is no vacuum, go to step 4).
- If there is vacuum, check for voltage at anti-afterburn control solenoid valve (Blue/Yellow wire). If there is no voltage, go to Trouble Shooting. If there is voltage, disconnect vacuum hose number 21 from anti-afterburn valve. Check for vacuum at the hose.
- If there is no vacuum, check for leaks or disconnected hose. If there are no defects, replace the anti-afterburn control solenoid valve and retest. If there is vacuum, replace the anti-afterburn valve and retest.
- Jack up the front of the vehicle and support with safety stands. Block the rear wheels and set the parking brake. Place the shift or selector lever in second or 2 position and accelerate. Release the throttle suddenly and check for vacuum during deceleration above 3000 RPM (man. trans.) or above 15 MPH (auto. trans.).
- If there is vacuum, go to WARM ENGINE test. If there is no vacuum, check for voltage at the anti-afterburn control solenoid valve above 3000 RPM (man. trans.) or above 15 MPH (auto. trans.).
- If there is voltage, go to Trouble Shooting. If there is no voltage, disconnect vacuum hose number 21 from the anti-afterburn valve and check for vacuum above 3000 RPM (man. trans.) or above 15 MPH (auto. trans.).
- If there is vacuum, replace the anti-afterburn control valve and retest. If there is no vacuum, disconnect vacuum hose number 20 from anti-afterburn valve and check for vacuum. If there is no vacuum, check for disconnected hoses or leaks and retest. If there is vacuum, replace the anti-afterburn valve and retest.