EGR System
- Disconnect vacuum hose from EGR valve and, using a 3-way union, connect a vacuum gauge. Check that engine starts and runs at idle. See Fig 1.
- Check TVSV with coolant temperature below 122°F (50°C). Check that vacuum gauge indicates 0 at 3000 RPM.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Check TVSV and EGR vacuum modulator with engine hot. Check that vacuum gauge indicates low vacuum at 3000 RPM.
- Apply vacuum directly to the EGR valve with the engine idling. Engine should run rough or die. Reconnect vacuum hose to proper locations. Engine should run smooth at idle. If no problem is found with this inspection, system is OK.