Operation CHARM: Car repair manuals for everyone.

Fuel System Pressure, Checking






Fuel system pressure, checking

Note! Some variation in the illustrations may occur, but the essential information is always correct.






Check the fuel pressure see: Diagnostics, Vehicle communication, ECM, Parameters, Fuel pressure.

Absolute pressure: Fuel pressure in fuel system + air pressure.
Relative pressure: Fuel pressure in fuel system.
The air pressure is approx. 100 kPa at sea level. VIDA measures the fuel pressure in absolute pressure. External pressure gauge (pressure gauge) measures the fuel pressure in relative pressure.

Fuel line pressure. Refer to: Specifications Specifications, Mechanical

The following method must be used when reading the fuel line pressure on the fuel rail:




Engagement of fuel pressure gauge.
Supplement the pressure gauge with adapter and nipple before use.
- 999 5011 MANOMETER 999 5011 Manometer
- 998 9725 Adapter 998 9725 Adapter
- 999 5479 ADAPTER 999 5479 Adapter
Connect the adapter to the valve on the fuel rail in the locked position (image 1, valve closed).
Set the cock on the pressure gauge in the direction of the nipple.
999 5479 ADAPTER 999 5479 Adapter
Connect the pressure gauge's other connection to the fuel drain equipment.
- 981 2270 PUMP TROLLEY 981 2270 Pump Trolley
- 981 2273 PUMP 981 2273 Pump
- 981 2282 Tank 981 2282 Tank
Unlock the adapter (illustration 2, valve open).
Start the engine.
Read off the relative pressure.




Disengagement of fuel pressure gauge.
Ignition off.
Start the draining unit.
Set the cock on the pressure gauge to the central position.
Secure the adapter (image 1, valve closed).
Remove the adapter from the valve.
Stop the draining unit.
Reset the equipment.