System Testing
- Connect a vacuum gauge to distributor main diaphragm hose and another vacuum gauge to distributor sub-diaphragm hose. See Fig 1. If equipped with high altitude compensation system (HAC), disconnect lower vacuum hose of HAC valve and connect it to intake manifold.
- Warm up engine to normal operating temperature. Pinch hose between vacuum pipe and vacuum transmitting valve (VTV). Increase engine speed to 2500 RPM and release hose. Vacuum gauge should indicate high vacuum within 2-5 seconds after releasing hose.
- Remove hose from VTV on vacuum pipe side. Vacuum gauge reading should drop rapidly to zero. Remove vacuum gauge and reconnect hoses.
- Remove distributor cap and rotor. Apply vacuum to diaphragms and verify that vacuum advancer moves. Reinstall rotor and cap. If system performed as described, testing is complete. If not, check individual components. See COMPONENT TESTS .
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002