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Fuel Injector Leakage

NOTE: Always use new fuel injector seals, moistened with clean engine oil. Take care not to damage the seals during installation.

Ensure system fuel pressure is Okay. See FUEL PRESSURE REGULATOR .

  1. Disconnect vacuum hose from fuel pressure regulator. Disconnect harness connector(s) from fuel injector(s). Disconnect fuel intake line and lift out upward (with fuel injectors).
  2. Connect one terminal of each fuel injector to be tested, to engine ground using adapter cable from (VW 1594).
  3. Connect second terminal of fuel injectors (one at a time) to remote positive cable connectors, using remote control (VW 1348/3A), adapter lead (VW 1348/3-2) and auxiliary cable. See Fig 1.
  4. Connect (VAG 1598) test box to Engine Control Module (ECM) harness connector using adapter cable (VAG 1598/5). See CONNECTING VAG 1598 TEST BOX .
  5. Switch ignition to ON position. Bridge test box terminals No. 3 and 10 using adapter and in-line fuse (8-Amp). Electric fuel pump must run.
  6. Check fuel injectors visually for leaks.
  7. Not more than 2 drops of fuel per minute (maximum) is allowed to leak from each injector.
  8. If fuel leakage is greater: Switch ignition to OFF position. Replace leaking fuel injector(s), replace seal(s).
  9. To test fuel injector quantity. See FUEL INJECTOR VOLUME .
Fig 1: Connecting Fuel Injector For Testing
G00160045Courtesy of AUDI OF AMERICA, INC.