SEAT Workshop Service and Repair Manuals

Checking injectors with vacuum   Note t  Leaking control valves of the injectors (piezo injectors) may lead to uneven run of the engine or even cause problems when starting. t  To check regulating valves for soiling (and with it higher leakage), further to the "classical" return quantity measurement, checking with vacuum is also possible. t  Observe instructions for working on fuel system → Chapter Special tools and workshop equipment required

t  Vacuum pump -VAS 6213-

t  Prepare an -adapter- with return line of the injector. »Carry out the following work sequence« –  Collect escaping fuel with a cleaning cloth. –  Open the supports of the return line of the injector to be tested using a fine tipped screwdriver and a pliers.

Always renew clips.

–  Pull off return line in direction of arrow.   WARNING t  The fuel and the fuel lines in the fuel system can become very hot (danger of scalding)! t  Fuel system is under pressure! The fuel supply system is also under pressure. Before opening the system, place cloths around the connections. Then carefully loosen connection to release the pressure! t  Wear eye and hand protection when performing any type of repair work on the fuel system!

–  Undo fuel high-pressure line -2-. To do this, only undo union nuts on high-pressure accumulator -1-. –  Connect the adapter that had previously been cleaned using compressed air to the injector that should be tested.

–  Use hand-operated vacuum pump -VAS 6213- to generate vacuum of approx. 500 mbar. If injector is OK, pressure remains constant for 30 s. If injectors are defective, the pressure drops within 2 ... 3 seconds back to 0 bar. Repeat check is necessary, observe pressure loss at hand-operated vacuum pump -VAS 6213-. –  Renew injectors → Chapter.