Testing Return Fuel Pressure - Yanmar BY Series Service Manual

FUEL SYSTEM
6. Repeat procedure at the outlet end of the fuel
fine filter (Figure 6-5, (2)).
Specification
Inspection Item RPM
Fuel Feed Pump
Pressure All
(Minimum)
Results
• If pressure reading is not within specification,
inspect pre-filter (if equipped), fuel filter / water
separator, fuel fine filter, and fuel feed pump.

Testing Return Fuel Pressure

CAUTION
• ALWAYS be environmentally
responsible.
• Follow the guidelines of the EPA or
other governmental agencies for the
proper disposal of hazardous
materials such as engine oil, diesel
fuel and engine coolant. Consult the
local authorities or reclamation facility.
• NEVER dispose of hazardous
materials irresponsibly by dumping
them into a sewer, on the ground, or
into ground water or waterways.
• Failure to follow these procedures may
seriously harm the environment.
Note: This test is dependent on the fuel supply.
Test the low-pressure fuel system prior to
performing this test. See Measuring Fuel
Feed Pump Pressure on page 6-11.
1. Assemble a tee, hose, and 0 - 100 kPa
(0 - 15 psi) pressure gauge.
6-12
Specification
5 bar (73 psi)
0000013en
Figure 6-6
2. Disconnect the hose from the fuel return line
(Figure 6-6, (1)).
3. Connect test gauge assembly between
disconnected ends. Install and tighten hose
clamps.
4. Start engine and allow speed to stabilize at
normal low idle.
5. Read and record pressure.
Specification
Inspection Item RPM
Return Fuel
All speeds
Pressure
Results
• If test pressure reading is not within
specifications, find and correct the return fuel
restriction.
BY Service Manual
Tests and Adjustments
(1)
0003634A
Pressure
1.9 kPa (0.28 psi)
(7.6 in.Aq)