Stationary engine 3.8 锟斤拷 0.2 bar
Engine idling 3.3 锟斤拷 0.2 bar
NOTE: The seal or sealing ring in the brass closure cap is not exchangeable. It must therefore be used only once.
Tightening torque of new brass closure cap 2.5 锟斤拷 0.5 Nm(2.0 锟斤拷 0.5 ftlb.).
2 Check volume supply of fuel pump.
Precondition:
Fuel filter and electrical supply OK.
1. Relieve pressure in fuel tank by opening tank cap.
2. Connect Porsche System Tester 2.
3. Remove complete air filter system.
4. Detach fuel return line (A/F 17 mm) from the engine compartment (left), taking care to hold it fast (A/F 17 mm). Collect residual fuel.
Observe safety regulations.
5. Connect fuel hose (shop-made, approx. 1.5 meters long) to the fitting and hold in a measuring container.
6. Actuate fuel pump with the Porsche System Tester 2 and allow fuel to flow into the measuring container for 30 seconds.
Quantity supplied must be at least 850 cm3/30 s, i.e. after 30 seconds at least 850 cm3 of fuel must be in the measuring container.
NOTE: It is essential to observe safety regulations for handling fuel.
3 Check triggering of fuel injectors.
The fuel injectors can be individually suppressed with the Porsche System Tester 2 in the menu "Drive link active". The engine idle speed
decreases if triggering is OK.
If no drop in rpm can be detected, check triggering as follows:
a) B+ supply
1. Remove connector of fuel injector to be checked.
2. Connect voltmeter to the valve plug contact, terminal 1, and ground using an auxiliary cable.
3. Switch on the ignition.
Display: battery voltage
If meter does not read battery voltage, check wiring according to wiring diagram for continuity or short circuit.
b) Coil resistance of fuel injectors
1. Remove connector of fuel injector to be checked.
2. With an ohmmeter, measure resistance between terminals of fuel injector.
Display: 11 - 13 ohms
c) Injection output stage (negative supply)
1. Connect special tool V.A.G 1315 A/1 between fuel injector and connector.
2. Connect engine tester according to manufacturer's instructions. Connect cable for special input to special tool.