Fig. 223 Remove the hose for vacuum sensor from the
fuel pressure regulator and plug up the
(9) Measure the fuel pressure; it should range from
265Kpa-304KPa. If the pressure exceeds 304KPa, you
shall replace fuel pressure regulator; if the pressure is lower
than 265KPa, you shall check the following parts: the fuel
hose and its connectors, the fuel pump, the fuel
filter, and the fuel pressure regulator.
(10) Remove the connection wire from the check connector.
(11) Start the engine.
(12) Remove the hose for vacuum sensor from the fuel
pressure regulator and plug up the hose’s end with a plug
(See Fig.223).
(13) Measure the fuel pressure when the engine is idling,
which should range from 265KPa to 304KPa.
(14) Connect the hose of vacuum sensor to the fuel
pressure regulator.
(15) Measure the fuel pressure when the engine is idling, which should range from 206KPa to
255KPa; If not so, you shall check the hose and fuel pressure regulator.
(16) Stop the engine.
(17) Check whether the fuel pressure is within a specified range for five minutes or above. At the moment, the pressure
should reach 147Kpa or above. If the fuel pressure is not within the specified range, you shall check the fuel pump, the fuel
pressure regulator or the injector.
(18) Remove the cable of battery’s negative pole and detach the special tools. Prevent fuel splashing during the process.
(19) Connect the fuel inlet hose to the fuel delivery pipe with two new washers and the connection bolt. The fastening torque
is 29Nm.
(20) Finally, check whether there is any fuel leakage.
Detaching the fuel pressure regulator (See Fig. 224):
1. Remove the hose for vacuum sensor from the fuel pressure regulator.
2. Remove the fuel return hose from the fuel pressure regulator.
Note: please place a container or towel under the fuel pressure regulator.
3. Remove the fuel pressure regulator
(1) Remove the two bolts and pull out the fuel pressure regulator.
(2) Remove the O-ring from the fuel pressure regulator.
Install the fuel pressure regulator:
1. Install the fuel pressure regulator
(1) Smear a small amount of gasoline on a new O-ring and fix it onto the fuel pressure regulator (See Fig. 225).
(2) Rotate the fuel pressure regulator to the left and right alternately and mount it onto the transmission pipe (See Fig. 226).
(3) Check whether the fuel pressure regulator can rotate smoothly. If not so, the O-ring may be clamped too tightly. In this
case, you shall remove the pressure regulator and repeat the above step 2 and step 3.
(4) Install the pressure regulator by using two bolts. The fastening torque is 9.3Nm.
2. Connect the fuel return hose to the fuel pressure regulator.
3. Connect the hose of vacuum sensor to the fuel pressure regulator
103
Summary of Contents for JL481Q
Page 1: ......
Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...