LEMON Manuals: Even more car manuals for everyone
Home >> Honda >> 1989 >> Civic Si >> Repair and Diagnosis >> External Pages >> Different car >> Section 13 (System/Component Tests - CARBURETED) >> Ignition System >> Timing Control Systems >> Ignition Control Thermovalve

Ignition Control Thermovalve

WARNING: This page is about a different car, the 1989 Honda Prelude. However, it is still accessible from the selected car via links, so may be relevant.
  1. With engine cold, start engine and check for vacuum to outer diaphragm of vacuum advance unit. If vacuum is present, go to next step. If vacuum is not present, check vacuum supply to upper fitting of thermovalve on Prelude. On Accord check vacuum supply to thermovalve. If vacuum supply is okay, replace thermovalve. If not, repair as necessary.
  2. Warm engine to operating temperature. Check for vacuum at outer diaphragm of distributor vacuum advance unit. If vacuum is present, replace thermovalve. If vacuum is not present, valve is functioning properly.