lemon-mirror:
Home >> Volkswagen >> 1985 >> Vanagon Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Ignition System - Electronic >> Testing >> Vacuum Advance Test

Vacuum Advance Test

  1. Connect tachometer and timing/advance light to engine. Connect Vacuum Advance Tester (VAG 1368 ) between throttle valve housing and vacuum advance diaphragm. Remove both plugs from idle stabilizer and connect together.
  2. Disconnect vacuum hose from retard diaphragm and plug vacuum retard hose. Start and run engine at 900 RPM. Bring timing mark back to pointer by using dial on timing light. Initial (base) ignition timing should be indicated.
  3. Increase engine RPM until vacuum reading on tester is higher than 11 in. Hg (270 mbar). Turn tester knob so that tester holds vacuum on vacuum advance diaphragm.
  4. Return engine to 900 RPM. Decrease vacuum to 6-6.7 in. Hg (190-230 mbar). Bring timing mark back to pointer by using dial on timing light and read vacuum advance.
  5. To determine total vacuum advance, subtract base ignition timing from reading. After testing, reconnect idle stabilizer plugs. Reconnect vacuum hoses, adjust base ignition timing and idle speed.
· About lemon-mirror