Audi Workshop Service and Repair Manuals

Checking tandem pump - vehicles with 2-valve engine Special tools and workshop equipment required

t  Tandem pump tester -VAS 5187- with banjo bolt -VAS 5187/1A-

Procedure Observe test conditions → Chapter. Observe safety precautions → Chapter. Observe rules for cleanliness → Chapter. Engine cover panel (version 1): –  Lift engine cover panel at the sides -arrows 1- and pull off towards the front -arrow 2-.

Engine cover panel (version 2): –  Lift off engine cover panel (outside -1- and inside -2-) by pulling up evenly.

All vehicles (continued): –  Pull cover off air duct (release clips on sides) -arrows-.

–  Unclip air duct at the bottom by releasing clips -arrows-. –  Detach air duct (bottom) together with air hose.

–  Unplug electrical connector -1- at air mass meter -G70-. –  Detach vent hose -3- and air hose -2-. –  Unscrew bolt -4- and remove air cleaner housing.   WARNING t  The fuel system is pressurised. Wrap a cloth around the connection before opening the system. Then release pressure by carefully loosening the connection. t  In extreme cases the temperature of the fuel lines and the fuel can be up to 100 °C after the engine is switched off. Allow the fuel to cool down before disconnecting the lines - danger of scalding. t  Wear protective gloves. t  Wear safety goggles.

–  Remove screw plug -arrow-.   Note Tandem pump is shown with engine removed for illustration purposes.

–  Connect tandem pump tester -VAS 5187- with banjo bolt -VAS 5187/1A- as shown in the illustration. –  Re-install air cleaner housing with air mass meter. –  Start engine. –  Increase engine speed to 4000 rpm. –  Read off pressure indicated on pressure gauge: l  Specification: at least 7.5 bar If specification is not obtained: –  Clamp off return hose between fuel filter and tandem pump using hose clamp. –  Increase engine speed to 4000 rpm. –  Read off pressure indicated on pressure gauge: l  Specification: at least 7.5 bar If specification is now obtained: pressure is being lost at unit injectors. –  Renew O-rings at unit injectors. If specification is not obtained: –  Renew tandem pump → Chapter.   Note After removing pressure tester, tighten screw plug to 25 Nm. Renew seal.