EGR Valve Flow Test

SYMPTOMS
A faulty EGR system can cause ignition ping, rough idle, engine stalling, sags or hesitation, and/or lack of performance. It is important that this system be free from leaks. Any hoses that are cracked or leaking should be replaced.

Inspect all vacuum hoses and connections, and replace any that are cracked, hardened, or melted.

EGR VALVE TEST
1. Remove EGR Valve from engine.
2. Apply a minimum of 15 in Hg to the valve diaphragm.
3. Check for movement of valve stem.
4. If there is no movement, replace EGR valve and transducer/solenoid as an assembly.
5. If the stem moves maintain constant vacuum supply. Valve should stay open for 30 seconds. If the valve does not stay open, replace EGR valve and transducer/solenoid as an assembly.
6. If the valve operates properly. Check for a clogged control valve, clogged back pressure tube, or exhaust passages in the cylinder head. Repair as necessary.