Pinpoint Test D: Low Pressure Fuel Line Pressure Tests
- D1: LOW PRESSURE FUEL LINE PRESSURE TEST 1 WARNING: This procedure involves fuel handling. Be prepared for fuel spillage at all times and always observe fuel handling precautions. Failure to follow these instructions may result in personal injuryNOTE: This procedure involves disconnection of fuel lines. Place suitable absorbent material around the fuel line to be disconnected, to absorb any spillage when connecting the fuel pressure gauge.
- Make sure the vehicle is in Park and apply the parking brake
- Set ignition status to OFF
- Disconnect the fuel supply line from the low pressure fuel pump fuel supply connection
- Connect the manufacturers approved fuel pressure gauge in the fuel supply connection on top of the low pressure fuel pump flange. Remove the absorbent material and dispose of safely
- Set ignition status to ON
- Record the fuel pressure reading
Is the fuel pressure >4.5bar?
Yes: GO to D2.
No: Remove the fuel pump module flange (to allow access to the fuel lines on the underside of the fuel pump module flange. (Refer to: FUEL TANK AND LINES Inspect low pressure fuel pump internal fuel lines from any leakage, blockage or de-latching. Inspect in-tank fuel filter from blockage. Check if the pump pressure relief valve is jammed open or leaking, Fuel pump module pressure regulating valve jammed open or leaking. Repair as required. If no fault found, GO to PINPOINT TEST F .
- D2: LOW PRESSURE FUEL LINE PRESSURE TEST 2 NOTE: This procedure involves disconnection of fuel lines. Place suitable absorbent material around the fuel line to be disconnected, to absorb any spillage when connecting the fuel pressure gauge.
- Reconnect the fuel supply line to the low pressure fuel pump fuel supply connection
- Disconnect the low pressure fuel supply line from the fuel filter
- Connect the manufacturers approved fuel pressure gauge in the fuel line between low pressure fuel pump and fuel filter. Remove the absorbent material and dispose of safely
- Set ignition status to ON
- Record the fuel pressure reading
Is the fuel pressure >4.4bar?
Yes: GO to D3.
No: Inspect low pressure fuel line between low pressure fuel pump and engine mounted fuel filter. Repair as required
- D3: LOW PRESSURE FUEL LINE TEST 3
- Disconnect the pipe which connects the fuel filter and HP fuel pump from the fuel filter
- Connect the manufacturers approved fuel pressure gauge between the fuel filter and the pipe to the HP fuel pump
- Set ignition status to ON
- Record the fuel pressure reading
Is the fuel pressure >4.3bar?
Yes: GO to D4.
No: Faulty fuel filter. Replace fuel filter
- D4: LOW PRESSURE FUEL LINE TEST 4
- Disconnect the fuel supply pipe from the HP fuel pump
- Connect the manufacturers approved fuel pressure gauge in the fuel line between the fuel supply pipe and the HP fuel pump
- Set ignition status to ON
- Record the fuel pressure reading
Is the fuel pressure >4.3bar?
Yes: Check the HP fuel pump inlet for any blockage due to debris. If no fault found, GO to PINPOINT TEST E .
No: Check the fuel line between the HP fuel pump and fuel filter. Replace or repair fuel line as necessary and retest