Camry, Celica, Pickup & 4Runner
- Check and clean vacuum modulator filters with compressed air before proceeding with test. On California carbureted Pickup and 4Runner, disconnect and plug vacuum hose at distributor main diaphragm.
- On all models, disconnect vacuum hose from EGR valve and, using a "T" connector, connect a vacuum gauge. Check that engine starts and runs at idle.
- Check BVSV with coolant temperature below 113°F (45°C) on Camry and 86°F (30°C) on all others. Check that vacuum gauge indicates zero at 2500 RPM on Camry, 3000 RPM on carbureted Pickup and 4Runner, and 3500 RPM on Celica and fuel injected Pickup and 4Runner.
- Check BVSV and EGR vacuum modulator with engine hot. Vacuum gauge should indicate low vacuum at 2500 RPM on Camry, 3000 RPM on Federal carbureted Pickup and 4Runner, and 3500 RPM on Celica and fuel injected Pickup and 4Runner. High vacuum reading should be observed at 3000 RPM on California carbureted Pickup and 4Runner.
- On all except California carbureted Pickup and 4Runner, disconnect vacuum hose from port "R" of EGR vacuum modulator and connect port directly to intake manifold vacuum.
- Vacuum gauge should indicate high vacuum at 2500 RPM on Camry, 3000 RPM on Federal carbureted Pickup and 4Runner, and 3500 RPM on Celica and fuel injected Pickup and 4Runner. Disconnect vacuum gauge and reconnect hoses to proper locations.NOTE: This will cause slight engine misfire due to a large amount of exhaust gas being injected into intake manifold.
- On all models, with engine idling, apply vacuum directly to EGR valve. Engine should run rough or die. Remove vacuum and reconnect vacuum hoses to proper locations. Engine should run smooth. If no problem is found with this inspection, system is okay.