LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1985 >> Land Cruiser >> Repair and Diagnosis >> Engine Performance >> System >> EGR Function Testing >> Component Testing >> Vacuum Modulator
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Vacuum Modulator

  1. Disconnect vacuum hoses from ports "P", "Q" and "R" of vacuum modulator. Plug ports "P" and "R" (2 ports on same side) and blow through port "P" (single port on opposite side). Air should escape freely from filter.
  2. Start engine and run at 2000 RPM on Camry, 3000 RPM on Celica, Pickup and 4-Runner, or 2500 RPM on all other models. Repeat blowing test. There should be strong resistance to air flow through modulator. If not, replace modulator. Reconnect vacuum hoses to proper locations.