volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

ABOUT US
Residual pressure and fuel pressure regulator - check > < Component checks

Polo Mk4

Injection valves - check
   
Injection valves - check

Check sealant and jet form
Special tools and workshop equipment required
t  Torque wrench - 5 to 50 Nm ( enc. 1/2") -VAG 1331-
t  Auxiliary measuring cable set -VAG 1594A-
t  Digital potentiometer (included in VAG 1594C) -VAG 1630-
t  Graduated container.
Test conditions
l  The fuel pressure must be correct, check → Chapter.
Test sequence
–  Remove air filter set → Chapter.
   
–  Disconnect the 2-pole connector from the Coolant temperature sensor -G62--arrow-.
  R24-0012
–  Disconnect the 4-pole connector from the Ignition transformer -N152--arrow-.
  N28-0175
–  Connect the Digital potentiometer (included at VAG 1594 C) -VAG 1630- using the Auxiliary measuring cable set -VAG 1594C-to connector contacts -1-+-2- and adjust connected side to 15 kΩ.
–  Disconnect the injection valve connectors in the fuel rail.
–  Remove the fuel rail with all injection valves from engine cylinder head (fuel lines remain connected).
  S24-0342
–  Keep a small graduated container under the injection valve to be tested and couple its connector.
–  Someone else must operate the Starter -B-. The injection valve should inject in pulses.
–  Repeat test on the other injection valves. Ensure that only the injection valve being tested is supplied.
–  Then check the injector valve sealant. Fuel loss cannot exceed 2 drops a minute.
If fuel loss is greater:
–  Turn ignition off.
–  Replace defective injection valve.
Injection valves are installed in the reverse sequence, observing the following:
t  Rings on all injection valves should be replaced and thoroughly lubricated with clean engine oil.
t  Place the injection valves vertically and in their proper position in the fuel rail and fasten them with safety clips.
t  Install fuel distributor with injection valves on cylinder head and press in a uniform way.
  R24-0015

Residual pressure and fuel pressure regulator - check > < Component checks