Air Pump Injection System (AP): Notes
- Start and warm engine to normal operating temperature. Observe direction of airflow within first 3 seconds. Air should flow to exhaust ports for first 3 seconds. After 3 seconds, airflow should switch to air cleaner. See Fig 1
.
- If system does not operate as described, go to next step. If system operates as described, air pump injection system is functioning properly. Check for manifold vacuum signal at air management valve with engine idling. Vacuum should be 10 in. Hg. Repair as required.
- Turn ignition on with engine off. Disconnect air management valve electrical connector, and connect a test light between connector terminals. If test light does not glow, go to next step. If test light glows, check for short in wire from air management valve solenoid to ECM. Replace wire if shorted. If wire is okay, replace ECM.
- Install jumper wire between White and Black wires of DLC, located behind left kick panel, near ECM. See Figure
.
- If test light still does not glow, go to next step. If test light glows, check for poor air management valve solenoid electrical connector or faulty solenoid. If connector and solenoid are okay, replace air management valve.
- Connect test light between air management valve solenoid terminal "A" (White/Yellow wire) and ground. See Fig 1
. If test light does not glow, check for blown 10-amp fuse No. 8 in interior fuse box. If test light glows, go to next step.
- Check for open in Light Green/Black wire from solenoid to ECM. If wire is okay, check resistance of solenoid windings. If resistance is less than 20 ohms, replace air management valve.
Courtesy of ISUZU MOTOR CO.