System Testing
- Cold start the engine and run at idle until normal operating temperature is attained.
- Remove the hose (Green stripe) from the injection mixer. Connect vacuum pump to hose end.
- Disconnect the solenoid valve connector and apply 3.9 in. Hg of vacuum. If idle becomes unstable or the engine stalls with vacuum applied, the EGR system is okay.
- Reconnect solenoid valve connector and apply 3.9 in. Hg of vacuum. If engine performance remains stable (no stall or idle degradation) the negative chamber of the EGR valve is open to atmosphere and EGR is okay. If unstable idle occurs, the solenoid valve is staying closed (inoperative) and must be replaced.