Volkswagen Workshop Service and Repair Manuals

Checking injectors

Special tools and workshop equipment required

t	Torque wrench (5…50 Nm) -V.A.G 1331-

t	Remote control for V.A.G 1348 -V.A.G 1348/3A-

t	Adapter cable -V.A.G 1348/3-2-

t	Auxiliary measuring set -V.A.G 1594 C-

t	Injection rate tester -V.A.G 1602-

Checking injectors for leaks and quantity injected Test prerequisite l  The fuel pressure must be OK → Chapter. l  Engine and fuel temperature: approx. 20 °C. Test procedure

–  Disconnect connector from coolant temperature sender -G62--arrow-.

–  Pull connectors off ignition coils -arrows-.

–  Disconnect connectors -1- from injectors. –  Remove securing bolts -2-. –  Pull fuel rail with injectors out of mounting in intake manifold. Do not disconnect fuel hoses. Insert fuel rail loosely in intake manifold to prevent any dirt from entering. –  Connect right contact and battery positive (+) with auxiliary cables from auxiliary measuring set -V.A.G 1594C- so that fuel pump runs.

–  Connect a contact of injector to be tested to engine earth using auxiliary cables from auxiliary measuring set -V.A.G 1594C-. –  Connect second injector contact with auxiliary cable to remote control for V.A.G 1348 -V.A.G 1348/3A- using adapter cable -V.A.G 1348/3-2-. –  Connect crocodile clip to positive battery pole in engine compartment. –  Remove three measuring containers from injection rate tester -V.A.G 1602-. –  Pull fuel rail out of intake manifold. –  Position measuring glass under injector to be tested. –  Operate remote control for V.A.G 1348 -V.A.G 1348/3A- for 30 seconds. –  Repeat check on other injectors.   Note Use one measuring glass per injector. –  After all injectors have been activated, place measuring beakers on a level surface and compare the quantity injected. Specification: 85…91 ml per injector. If the measured values of one or more injectors are above or below the prescribed specifications: –  Renew defective injector → Chapter. Checking for leaks Special tools and workshop equipment required

t  Digital potentiometer -V.A.G 1630- Test prerequisite l  The fuel pressure must be OK → Chapter. l  Engine and fuel temperature: approx. 20 °C. l  Fuel rail is removed. –  Connect digital potentiometer -V.A.G 1630- using auxiliary cables from auxiliary measuring set -V.A.G 1594- to connector contacts 1 + 2 and set connected side to 15 kΩ.

–  Hold a small container under the injector to be checked and pull connectors off all other injectors. –  Ask another person to operate the starter. No more than 2 drops/min must escape from each injector. If the fuel loss is greater: –  Switch off ignition. –  Renew defective injector → Chapter. Install injectors in reverse order. In the process, note the following: l  Renew O-rings on all injectors and lightly moisten with clean engine oil. l  Fit fuel rail with secured injectors onto intake manifold and tighten evenly.