Impco HHI, Service Manual

Page: 464 / 485

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2. Relieve the LPG fuel system pressure. Refer
to III. LPG Fuel System Pressure Relief.
3. Remove the air intake duct.
4. Remove the retaining pin holding the fuel hose
fitting and remove fuel hose.
5. Remove two hoses attached to the sides of the
Mixer.
6. Remove the electrical connector to the Throttle
Body.
7. Remove four screws on Mixer that secure the
Mixer, Adapter and Throttle Body to the Intake
Manifold
8. Lift up Mixer and Adapter, noting the place-
ment of the O-rings on the neck or inlet of the
Throttle Body. Three O-rings are used: two
are quad seals with an “X” cross section and
one has a round cross section.
9. Remove gasket between Throttle Body and
Intake Manifold.
10. Remove O-rings from the Throttle Body neck.
INSTALLATION PROCEDURE
1. Lightly lubricate new O-rings with Vaseline or
petroleum jelly prior to installation.
Contamination of the HEGO sensor can re-
sult from the use of an inappropriate RTV
sealer or silicone spray products. Do not
use silicone sprays or hoses which are as-
sembled using silicone lubricants. Always
use “oxygen sensor safe” RTV sealant for
repair procedures. Silicon contamination
will cause a high but false HEGO signal vol-
tage (rich exhaust indication). The ECM will
then reduce the amount of fuel delivery to
the engine, causing a severe driveability
problem. If silicone contamination is sus-
pected, remove and visually inspect the
sensor element. If contaminated, the portion
of the sensor exposed to the exhaust
stream will have a white powdery coating.
Always be sure to eliminate the cause of
contamination before replacing the sensor.
2. Place the quad seals and third O-ring on the
neck of the Throttle Body, maintaining the
same order as before.
IMPORTANT
Verify that the quad seals rest flat against the neck
of the Throttle Body with no twists.
3. Carefully place the Adapter on top of the Throttle
Body, ensuring the seals properly seat and are
not twisted or pushed down.
4. Place Mixer on top of the Adapter.
5. Place gasket on top of Intake Manifold.
6. Align the holes of the Mixer, Adapter, Throttle
Body, Gasket and Intake Manifold and secure
with four screws.
Torque to 106 in. lbs. (12
Nm).
7. Attach the two hoses to Mixer.
8. Attach the air intake duct from the Mixer.
9. Reconnect negative battery cable.
10. Open LPG tank valve.
11. Start the vehicle and let run until it reaches nor-
mal operating temperature.
12. If a DTC code is found, refer to the Electrical
Section for further diagnosis.
XII. FUEL VAPOR HOSE--(EPR) TO FUEL MIXER
REMOVAL PROCEDURE
1. Disconnect negative battery cable.
2. Remove retaining clip from EPR end of hose and
remove hose from EPR port with Port Fitting.
3. Remove retaining clip from Mixer end of hose
and remove hose from Mixer with Port Fitting.
4. Remove Port Fittings from both ends of the
hose.
IMPORTANT
Hoses are designed for specific applications, DO
NOT use hose material or length other than speci-
fied by the OEM.
INSTALLATION PROCEDURE
1. Lightly lubricate Port Fitting O-rings with Vase-
line or petroleum jelly prior to installation.
2. Insert Port Fittings into each end of the hose and
secure with hose clamps.