DaimlerChrysler SPRINTER2006 Service Manual page 134

14 - 2 FUEL SYSTEM
If a high-pressure line connection is leaking, coun-
terhold and tighten the connection to specification
then perform this procedure again (Refer to 14 -
FUEL SYSTEM -
Replace any damaged, restricted or leaking high-
pressure fuel lines with the correct replacement
line.
Fig. 1 Typical Test for Leaks with Cardboard
1 - HIGH-PRESSURE LINE
2 - CARDBOARD
3 - FITTING
CAUTION: The high-pressure fuel lines cannot con-
tact each other or other components. Do not
attempt to weld high-pressure fuel lines or to repair
lines that are damaged. Only use the recommended
lines when replacement of high-pressure fuel line is
necessary.
DIAGNOSIS AND TESTING - AIR IN FUEL SYS-
TEM
Air will enter the fuel system whenever fuel supply
lines, separator filters, injection pump, high-pressure
lines or injectors are removed or disconnected. Air
trapped in the fuel system can result in hard start-
ing, a rough running engine, engine misfire, low
power, excessive smoke and fuel knock.
Inspect the fuel system from the fuel tank to the
injectors for loose connections (Refer to 14 - FUEL
SYSTEM - WARNING). Leaking fuel is an indicator
of loose connections or defective seals. Air can also
enter the fuel system between the fuel tank and the
fuel pump. Inspect the fuel tank module and fuel
lines for damage that might allow air into the sys-
tem.
STANDARD PROCEDURE).
With the DRBIII connected to the vehicle, select
Engine and the select Sensor Display. Page down to
view Fuel Pressure Set Point and Actual Fuel Pres-
sure. Start the engine and observe the Fuel Pressure
Set Point and the Actual Fuel Pressure. If the Actual
Fuel Pressure Oscillates above and below the Fuel
Pressure Set Point in a regular cycle, inspect the fuel
system for air intrusion.
If the Actual Fuel Pressure gradually drops below
the Fuel Pressure Set Point then spikes well above
the Fuel Pressure Set Point, replace the fuel pres-
sure soleniod (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL
REMOVAL), and recheck.
DIAGNOSIS AND TESTING - INJECTOR LEAK
QUANTITY
WARNING: REVIEW THE HIGH PRESSURE FUEL
SYSTEM WARNING BEFORE BEGINNING SERVICE
(Refer to 14 - FUEL SYSTEM - WARNING).
CRANKING TEST
NOTE: If an injector is found to be out of specifica-
tion, repeat this test procedure after the injector
replacement. Hydraulic flow will take the path of
least resistance and multiple failures may be identi-
fied.
Perform this test with the engine at operating tem-
perature, when possible. This test will assist in
determining a defective or internally leaking injec-
tor(s) is present by measuring the amount of fuel
return.
(1) Turn the ignition off.
(2) Remove the engine cover (Refer to 9 - ENGINE
- REMOVAL).
(3) Disconnect the fuel return hoses at the top of
the injectors.
(4) Pinch off the fuel return line at the banjo bolt
fitting of the fuel rail.
(5) Disconnect the fuel rail solenoid and camshaft
position sensor.
(6) Install the test vials onto the injectors and
secure with the return hose clips (Fig. 2).
PRESSURE SOLENOID
VA
-