Fuel Pressure Gauge, Installing (6-Cylinder Models; Fuel Pressure Gauge, Installing - BMW 5251 Service Manual

I
Fuel Tank and Fuel Pump
--
Fuel pressure gauge, installing
(6-cylinder models)
4
Remove fuel rail cover by prying off trim covers (arrows) and
removing nuts.
4
If
equipped, remove schraeder valve cap (arrow). Blow fuel
back through feed line using a brief burst of compressed air
(maximum 3 bar or 43.5 psi).
WARNING
-
Fuel in fuel line is underpressure (approx. 3
-
5 bar or 45
-
75psi) andmay be expelled underpressure. Do not smoke
or work near heaters or other fire hazards. Keep a fire ex-
tinguisher handy Before disconnecting fuel hoses, wrap a
cloth around fuel hoses to absorb any leaking fuel. Catch
and dispose of escaped fuel. Plug all open fuel lines.
Always unscrew the fuel tank cap to release pressure
in the tank before working on the tank or lines.
4
Attach fuel pressure gauge to BMW special tool 13 5 220
(T-fittlng) or equivalent and attach to schraeder valve.
WARNING
-
The fuel pressure gauge must be securely connected to pre-
vent it from coming loose underpressure.
CAUTION-
When using the BMWspecial tool, use care when turning the
T-handle in to open the schraeder valve. Screw the handle in
just until the schraeder valve opens. Turning the handle in too
far will damage the schraeder valve.
NOTE-
*
The schraeder valve must be opened to the fuel pressure
gauge connection. Either remove the valve using a stan-
dard tire valve removal tool or use the BMW special tool
15 5
220.
*
The fuel pressure gauge should have a minimum range of
0
to 5 bar (0 to 75 psi).
-
For vehicles without the schraeder valve on the fuel rail, at-
tach the fuel pressure gauge in line with the fuel supply line
to the fuel rail.