Fuel Pump: Testing and Inspection

Checking Delivery Pressure of Fuel Pump (M62)

Switch off ignition.


CAUTION!
The fuel in the fuel lines is under pressure (approx. 3 bar)!
Catch and dispose of escaping fuel.







Acoustic cover version 1:
(Acoustic cover screwed down)
Remove sealing caps (1). Release nuts (2).
Remove cover from cylinder head cover.







Acoustic cover version 2:
(Acoustic cover with press-stud fastener)
Press press-stud fasteners (1...4) in succession and simultaneously raise acoustic cover slightly. Remove acoustic cover when all four press-stud fasteners have been unlocked.

Installation:
Position acoustic cover and press down until press-stud fasteners (1...4) snap audibly into place.







Measuring valve on fuel rail:
Remove dust cap (1) from measuring valve on fuel rail.







Prepare special tool kit 13 5 220 (comprising 13 5 221 and 13 5 222).
Connect special tool kit 13 5 220 to pressure sensor of DIS Tester.
Connect pressure sensor to DIS Tester.







Unscrew check 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 check valve (1) until a pressure reading is indicated on DIS Tester.


CAUTION!
Do not under any circumstances screw in the check valve up to the mechanical stop. This could damage the valve in the pressure regulator housing.







Fuel hoses with quick-release coupling without integrated unlocking device:
Unlock and remove fuel feed line with special tool 16 1 050.

Installation:
Check sealing ring in quick-release coupling of fuel hose and sealing surface on fuel line for damage and replace if necessary.
Coat sealing ring in quick-release coupling of fuel hose with anti-friction agent.







Version, fuel hoses with integrated unlocking facility:
Press fuel hose (1) downwards and keep pressed.







Press unlocking ring (2) upwards, keep pressed and detach fuel hose (1).

Installation:
Check O-ring in fuel hose and sealing surfaces on fuel lines for damage; replace components if necessary.
Coat O-ring for assembly with anti-friction agent.







Connect special tool 13 5 270 to detached fuel hose and to open pipe neck.
Connect special tool 13 5 270 to pressure sensor (2) of DIS Tester.


Measuring fuel pressure:
- Connect pressure sensor to DIS Tester.
- Stan engine.
- Select measuring option.
- Multimeter function appears.
- Select pressure test.
- Read off fuel pressure.
Test pressure,

Injectors And Lines, Fuel Pressure Regulator M62:

Switch off engine.







Check fuel pump:
Fold right side trim in luggage compartment to one side. The relay bracket is installed above the battery.







Detach fuel pump relay (2).
Check whether fuel pump no longer starts up during engine starting procedure (engine fails to start).







Connect special tool 61 3 050 to terminal (87) and terminal (30).
Actuate button and read off delivery pressure on DIS Tester.
Delivery pressure,

Injectors And Lines, Fuel Pressure Regulator M62:

Keep special tool 13 3 010 available for further tests.
Further procedure for checks,
refer to Fuel pressure check.

Installation:
Interrogate fault memory of DME control unit. Check stored fault messages. Rectify faults. Now clear the fault memory.