LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 1986 >> Mirage Base >> Repair and Diagnosis >> Engine Performance >> System >> EGR System - Gasoline >> System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

System Testing

  1. Check vacuum hoses for proper routing (see underhood label), leaks or deterioration. Remove Green-striped hose which connects EGR valve and carburetor.
  2. Attach hand vacuum pump to EGR valve and try to create vacuum. If vacuum can be created, check hose leading from EGR valve to thermo valve for possible restrictions. If no restrictions can be found, thermo valve must be replaced.
  3. If no vacuum can be created, start engine and allow it to reach operating temperature. Attach hand vacuum pump to EGR valve and try to create vacuum. At least 20 in. Hg of vacuum should be obtained. This indicates EGR control valve and thermo valve are operating properly. While maintaining vacuum, engine should stall.
    NOTE: If EGR valve will hold vacuum, but engine does not stall, exhaust gas passage has restriction. EGR valve must be replaced.
  4. With engine idling, remove White vacuum hose from nipple of Vacuum Regulator Valve (VRV). Using hand vacuum pump, maintain vacuum of 20 in. Hg. If no vacuum can be created, there is a leak in VRV. If vacuum leak is indicated, VRV is normal. Reattach hoses to original locations.
scientia non olet · About LEMON Manuals