Celica, Corona, Land Cruiser & Pickup
- Using a 3-way connector, connect a vacuum gauge to EGR vacuum hose. Start engine and run at idle speed.
- With coolant temperature below 86°F (30°C), vacuum gauge should indicate zero at 2000 RPM. When engine is warm, low vacuum should be present.
- On Federal Pickup (except Cab and Chassis) and Land Cruiser, disconnect vacuum hose from EGR vacuum modulator port "R". Using a jumper hose, connect port "R" to intake manifold vacuum. Vacuum gauge should indicate high vacuum at 2000 RPM.NOTE: Engine will misfire slightly at this time, as a large amount of EGR gas enters.
- Reconnect all hoses and remove vacuum gauge. Apply manifold vacuum directly to EGR valve with engine idling. Engine should run rough or die.
- On Federal Pickup (except Cab and Chassis) and Land Cruiser, disconnect vacuum hoses from pipe "E" and "F" of VSV. Run engine at idle speed. Blow air into pipe "F" checking that VSV closes.
- Increase engine speed to above 1700 RPM. Blow air into pipe "F" checking that VSV opens. Reconnect vacuum hoses.
- If system performed as described, it is operating correctly. If not, test individual components and repair or replace as necessary.