Fuel System
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03.14.04 Air bubble formation in fuel system (Example)
Preparation:
Change fuel filter, if necessary
refer to 03.09 (item 1, bleed fuel system)
Testing device for fuel return 2300719/1
1. Disconnect hose from fuel return on block
fuel cooler outlet to fuel cooler.
2. Connect hose (ill.1/pos.1) of testing device
2300719/1 to block outlet.
3. Connect hose of testing device 2300719/1
with return hose to fuel tank.
4. Hold testing device, glass bulb upwards, or
fix it on the vehicle.
Procedure:
Check 1:
Ventilate fuel system by 6 times ignition ON. Observe the sight glass as to
complete ventilation of system (bubble-free fuel flow).
Result: If a bubble-free fuel flow cannot be achieved, search for the problem at the
suction side (from fuel tank to fuel pump).
Check:
1. Fuel in tank.
2. Tank suction pipe and fitting
3. Water separator leaky or contaminated.
4. Check all fuel lines connections and fittings in the feed line (suction
side) up to fuel pump intake.
After a bubble-free fuel flow can be achieved, continue with check 2.
Check2:
Start the engine and let it run at idle speed. Observe the glass bulb.
Result: If bubble formation starts, search for the problem in the unit injectors.
Probable contaminations on one or several nozzle elements cause a problem. Due
to compression/combustion pressure, gases enter the fuel system through the unit
injector nozzle(s). Investigate fuel injectors and replace defective one.
Check: Defective unit injector(s) is/are to be detected definitely by means of "manual
injection test method"
(manual injection test method, refer to 03.14.01 and 03.14.02)
If air bubble formation appears during load operation, continue with check 3.
Check 3:
Start the engine, bring it to operating temperature, test the vehicle under
operating conditions and observe the glass bulb.
Summary of Contents for Marine Engine 2012 Series
Page 35: ...General 35 65 Z001138 1_2013 02 01 Trouble Indication ...
Page 36: ...General Preliminary Service Manual MARINE 2012 Z001138 1_2013 02 01 36 65 ...
Page 51: ...General 51 65 Z001138 1_2013 02 01 G Notes on safety ...
Page 69: ...Engine Z001138 1_2013 02 01 4 87 Kapitel MOUNT BRACKET COVER T BELT GASKET SET ...
Page 154: ...Fuel System Z001138 1_2013 02 01 2 51 ...
Page 159: ...Fuel System 7 51 Z001138 1_2013 02 01 03 00 03 Unit injector ...
Page 190: ...Fuel System Z001138 1_2013 02 01 38 51 Schema Injection Timing Device ITD ...
Page 211: ...Cooling System 5 21 Z001138 1_2013 02 01 ...
Page 231: ...Electrical System Z001138 1_2013 02 01 4 47 ...
Page 235: ...Electrical System Z001138 1_2013 02 01 8 47 ...
Page 236: ...Electrical System 9 47 Z001138 1_2013 02 01 ...
Page 238: ...Electrical System 11 47 Z001138 1_2013 02 01 ...