Corolla Sedan L4-1587cc 1.6L DOHC (4A-F) (1987)
THERMAL VACUUM SWITCHING VALVE (TVSV) TEST:
1. Drain the coolant from the radiator into a suitable container.
2. Unscrew and remove the TVSV from the intake manifold.
3. Place the TVSV in a pan of cool water, (below 45°F).
4. Check that air flows from pipe J to pipe M and L. Fig. 43
Fig. 43 Testing TVSV Below 45 Deg F
5. Check that air flows from pipe K to pipe N.
6. If not as specified, replace the TVSV.
7. Heat the TVSV to between 63 - 122°F.
8. Check that air flows from pipe K to pipe L and N. Fig. 44
Fig. 44 - Testing TVSV Between 63-122 Deg F
9. Check that air flows from pipe J to pipe M.
10. If not as specified, replace the TVSV.
11. Heat the TVSV to above 154°F.
12. Check that air flows from pipe K to pipe M and L. Fig. 45
Fig. 45 - Testing TVSV Above 154 Deg F
13. Check that air does NOT flow from pipe J through any other pipes.
14. If not as specified, replace the TVSV.
15. Apply a suitable sealant to the TVSV threads and reinstall.
16. Refill the radiator with coolant.