BMW X5 Owners & Service Manuals

BMW X5: Fuel System (N62TU)

Fuel Pump With Drive And Line

NOTES ON FUEL PRESSURE CHECK (REFERENCE PRESSURE: ENVIRONMENT)

Feature of this version with ambient pressure:

The connection for the vacuum hose of the fuel pressure regulator is located between the throttle and the air cleaner or on the air cleaner.

Test precondition:

The correct fuel pressure regulator is fitted.

Description of operation:

The control function of the fuel pressure regulator must be guaranteed under all operating conditions. The fuel pump must always be able to generate a higher fuel pressure than the pressure regulated by the pressure regulator.

The injection rate is adjusted by means of the injection time; the injection time is controlled by the DME.

Description of operation: fuel return line

When the engine is at a standstill and the ignition key is in position 0, the fuel return line after the pressure regulator is at zero pressure.

Description of operation: pressure retaining function

The pressure regulator closes when the engine is at a standstill and the ignition key is in position 0. The fuel pressure in the delivery line is retained over an extended period. A non-return valve closes in the fuel pump.

These measures help to retain the fuel pressure in the fuel system. Extended starting times are thus avoided.

Complaint: drive characteristic faults, lack of power

If the measured value is less than the nominal value - 0.2 bar:

If the measured value is greater than the nominal value + 0.2 bar:

If measured value remains too high, then pressure regulator is in all probability faulty.

IMPORTANT: With less likelihood, the return line may be completely blocked. When the pressure regulator is removed, fuel could escape under pressure!

Complaint: starting problems

If the measured value has dropped by more than 0.5 bar:

If the measured value has now dropped by less than 0.5 bar, the following faults can be present:

If the measured value has dropped by more than 0.5 bar again:

NOTE:

CHECKING FUEL PUMP DELIVERY PRESSURE (N62TU2)

Special tools required:

Necessary preliminary tasks:

IMPORTANT: Fuel in fuel lines is under pressure (approx. 3-5 bar)! Catch and dispose of escaping fuel.

Remove dust cap on measuring valve of fuel rail.

Unscrew non-return valve (1) on special tool kit 13 5 220.

Mount special tool kit 13 5 220 on fuel rail and tighten knurled nut until hand-tight.

Start engine.

Screw in non-return valve (1) until a pressure reading is indicated on the DIS Tester.

Fuel Pump With Drive And Line
Fig. 1: Identifying Special Tool

IMPORTANT: Do not under any circumstances screw in the check valve up to the mechanical stop. This could damage the valve in the fuel rail.

Measuring fuel pressure:

Test Pressure:

INJECTORS AND LINES, FUEL PRESSURE REGULATOR N62 / N45 / N46

Fuel Pump With Drive And Line

Switch off engine.

Assemble vehicle and check fuel system for leaks.

Checking fuel pump:

Remove fuel pump relay.

Connect special tool 61 3 050 to terminal (87) and terminal (30).

Operate button and read off fuel pump delivery pressure at DIS Tester.

Fuel Pump With Drive And Line
Fig. 2: Identifying Special Tool And Terminals

Notes on FUEL PRESSURE CHECK.

Installation:

Now clear the fault memory.

READ NEXT:

 Engine Electrical System

 Troubleshooting

CONTENTS OF ENGINE ELECTRICAL SYSTEM GENERAL General Information -> Working on ignition system. -> Removing and installing electronic control units. -> Welding work (overload protection of co

 Ignition Wires, Spark

REPLACING ALL SPARK PLUGS (N42, N40, N46, N45, N52, N52K, N51) Special tools required: 12 1 171 12 1 200. Necessary preliminary tasks: Switch off ignition Remove ignition coils. Unscrew spark

SEE MORE:

 Leak-Testing Evaporator

Special tools required: 64 5 104 64 5 108 Necessary preliminary tasks: Remove expansion valve. Replace sealing rings (1) and coat with refrigerant oil. Fig. 90: Identifying Sealing Rings Mount special tool 64 5 108 and retainer (1) with screws of expansion valve. Tightening torque. Fig. 9

 Removing And Installing/Replacing Backrest Frame For Left Rear Seat (Through - Loading System)

Necessary preliminary tasks: Remove backrest cover. Remove retractor mechanism. Remove lock. Release screws (1). Installation: Replace screws and insert with Loctite. Tightening torque 52 26 07AZ. Remove lock for centre armrest. Fig. 160: Identifying Screw REMOVING AND INSTALLING/REPLACING

© 2019-2024 Copyright www.bmwx5info.com