Vacuum Control Valve
- Connect vacuum gauge between thermal vacuum valve and EGR valve. Increase engine speed to 1000 RPM (do not pull on STOP lever).
- Vacuum should measure 5.7-6.7 in. Hg on non-Turbo models, and 4.9-5.7 in. Hg on Turbo models. If not, check orifice to ensure it is clean. If level is too high, install a larger orifice. If level is too low, install a smaller orifice. If vacuum level cannot be correctly adjusted, replace vacuum control valve.