Carbureted Models
- Disconnect vacuum hose from EGR valve and connect vacuum gauge to hose. Remove control box from firewall and remove cover attaching screws. On all models, vacuum and voltage should be as shown in EGR SYSTEM TEST table.
EGR SYSTEM TEST
| Condition No. |
Engine Condition |
EGR Valve Vacuum |
| 1 |
Idle |
No |
| 2 |
3000 RPM |
2-6 in. Hg |
| 3 |
3000 RPM |
Less Than 2 in. Hg |
| 4 |
Hard Acceleration |
2-6 in. Hg |
| 5 |
Deceleration |
No |
- If there is no vacuum available for conditions No. 2 and No. 4, check for vacuum at inlet and outlet of thermovalve C. If there is no vacuum at outlet, replace thermovalve. If no vacuum at inlet, check vacuum line routing and repair or replace. Clean and retest.
- If vacuum is available on condition No. 1 or vacuum is greater than 2 in. Hg on condition No. 3, replace EGR control solenoid valve. Ensure vacuum hoses are routed properly.