Corolla & Tercel
- Disconnect vacuum hose from EGR valve and, using a 3-way union, connect a vacuum gauge to it. Start engine and check that engine starts and runs at idle.
- Check TVSV with coolant temperature below 122°F (50°C). Check that the vacuum gauge indicates zero at 3000 RPM.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Check TVSV and EGR vacuum modulator with engine hot. Check that the vacuum gauge indicates low vacuum at 3000 RPM.
- Apply vacuum directly to the EGR valve with the engine idling. Check that the engine runs rough or dies. Reconnect vacuum hose to proper locations. If no problem is found with this inspection, system is OK.