Volkswagen Workshop Service and Repair Manuals

Checking injectors Checking spray pattern and for leaks

Special tools and workshop equipment required

t	Torque wrench -V.A.G 1331-

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

t	Digital potentiometer -V.A.G 1630-

t	Measuring container

Test prerequisite The fuel pressure must be in order, checking → Chapter. Test procedure Engine codes AHW, AKQ, APE, ATN, AUS, AXP

–  Remove cover above camshaft housing -arrows-. –  Remove air filter → Fig.. Engine codes AZD, BCA, BCB –  Remove engine cover. Continuation for all engine codes

–  Pull 4-pin connector off coolant temperature sender -G62- with coolant temperature gauge sender -G2--arrow-.

–  Connect digital potentiometer -V.A.G 1630- using aux. cables from auxiliary measuring set -V.A.G 1594C- to connector contacts 3+4 and set connected side to 15 kΩ∼. –  Unclip wiring harness for injectors from intake manifold and thermostat housing.

–  Disconnect vacuum hose from fuel pressure regulator -arrow-. –  Remove fuel rail complete with all injectors from intake manifold (fuel hoses remain connected) → Item.

–  Hold a small container under the injector to be checked and pull connectors off all other injectors. –  Ask another person to operate the starter. Injector must issue pulsed spray. –  Repeat check on other injectors. Make sure that only the valve being tested is connected. –  Then check the injectors for leaks. No more than 2 drops/min must escape from each injector. If the fuel loss is greater: –  Switch off ignition. –  Renew defective injector → Item. Install injectors in reverse order. In the process, note the following: t  Renew O-rings on all injectors and lightly moisten with clean engine oil. t  Fit fuel rail with secured injectors onto intake manifold and tighten evenly.