Linhai HY740STL 2018, Service Manual, Page: 116 / 217

CHAPTER 3 ENGINE
M750L SERVICE MANUAL 18.0
CHAPTER 3 ENGINE PAGE 3-
85
being installed into, rather than directly to the seal ring itself. This will help
minimize the possibility of injector contamination.
Avoid applying lubricant over the director plate holes
– this may restrict injector
flow. Do not dip the injector tip in lubricant.
All Multec 3 and Multec 3.5 injectors come from the factory with the seal rings
attached. The re-use of seal rings is not preferred when replacing an injector. If
an injector is to be re-used, and no new seal rings are available, take care to
inspect each seal ring for signs of damage. Even minor defects in the seal ring
can lead to leakage. Take extra care in installing seal ring over flange of
injector inlet.
Carefully installing the harness connector will prevent terminal damage. Listen
for a positive audible click from the connector retention device
— this ensures
that it is fully engaged.
Avoid unnecessarily disconnecting/reconnecting the harness connector.
Wires routed in a manner that can allow them to become pinched between
components can result in a short circuit and a stuck open injector.
For injectors that require orientation for spray pattern, do not rotate the injector
in the fuel rail assembly to install the injector electrical connector. This may
dislodge the retaining clip, and result in improper spray orientation
3.18.2.11 Replacement Techniques
The following procedure outlines standard Multec 3 and Multec 3.5 Fuel Injectors
removal and replacement.
Warning: The injector and all associated hardware may be extremely hot.
Shut off ignition.
Disconnect negative battery cable to avoid possible fuel discharge if an
accidental attempt is made to start the engine.
Disconnect the electrical connector from the injector wiring harness.
Relieve fuel pressure
Remove the retaining clip from the fuel injector.
Remove the fuel line connection from the injector
Carefully clean debris from the interface surfaces. Do not damage seal mating
surfaces.
Remove the injector from the manifold
Apply a light coating of a lubricant to both the upper and lower injector seal ring
of the replacement injector.
Install the new injector into the manifold. Check that the injector is installed in
the original orientation to maintain proper spray targeting, and that the retaining
clip is properly seated on the injector and the fuel line
Install the retaining clip after connecting the fuel line
Tighten the injector mounting to the desired torque as mentioned in the
manufacturer manual
Tighten the fuel line
Re-install the injector electrical connector
Check for fuel leaks with the key “on” and the engine “off”
Start engine and verify proper operation
3.18.2.12 Interchange ability
The injector should be replaced in service only with an equivalent injector of the
same part number. On occasion, a new part number may supersede part
numbers. Consult the appropriate vehicle service manual and part number guide
for the latest replacement injector part number information.