Exhaust Gas Recirculation: Testing and Inspection

CHECKING REQUIREMENTS:
- Vacuum lines and intake manifold connections free of leaks.
- Vacuum lines not plugged or bent.
- Engine oil 50°C (122°F) minimum.




CHECKING PROCEDURE:
- Start engine and let idle.
- Disconnect vacuum hose at EGR valve.
- Connect US 8026 hand vacuum pump to EGR valve using spare piece of hose.
- Operate hand pump to create vacuum.

Idle quality must degenerate.

If NO (idle improves or stays the same):
- Check lines and connections for plugging; replace EGR valve if necessary.