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
| Cond. No. |
Condition of Engine |
EGR Valve Vacuum |
| 1 |
Idle |
No |
| 2 |
4500 RPM |
2-6 in. Hg |
| 3 |
4500 RPM |
less than 2 in. Hg |
| 4 |
Hard Acceleration |
2-6 in. Hg |
| 5 |
Deceleration |
No |
- If there is no vacuum available for conditions 2 and 4, check for vacuum at inlet and outlet of thermovalve C. If no vacuum is at outlet, replace thermovalve. If no vacuum is at inlet, check vacuum line routing and repair or replace. Clean and retest.
- If vacuum is available on condition 1 or vacuum is greater than 2 in. Hg on condition 3, replace EGR control solenoid valve. Ensure vacuum hoses are routed properly.