F300-HD_Engine-FU-Fuel_System-Part1
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PART 1 - PART 2 - PART 3 - PART 4
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EEE
F300
FUEL SYSTEM (HD-C Engine)
PRECAUTIONS 2 TROUBLE SHOOTING 2 IN-VEHICLE INSPECTION FU- 3 CARBURETOR 7 FUEL PUMP
FUEL FILTER
WNBBE-FU001
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PRECAUTIONS
1. Before working on the fuel system, be sure to disconnect the ground cable from the negative (_) terminal
of the battery.
2. When working on the fuel system, never allow any naked fire to be brought near the working site. Also,
never smoke cigarette or the like.
tion.
. Do not allow the fuel to get to any parts made of rubber or resin.
Do not work on the fuel system of morethan one vehicle at the same time. _ Be certain to keep each part ofthe fuel system from contamination.
Be very careful not to allow any dirt or the like be mixed into the fuel system during the servicing opera
7. Make sure to keep the working site clean. Also, be sure not to loose any part, specifically small parts. 8. Never loose nor mix up those pins, clips and springs with each other.
TROUBLE SHOOTING
Possible cause
Page
Engine will not start/hard to start (Only case where cranking by startor motor is normal)
Carburetor problems
Choke operation
Needle valve sticking or clogged Vacuum hose disconnected or
damage
Fuel cut solenoid vlave not open
Outer vent valve not open
Check choke eystem Check float and needle
Check fuel cut solenoid valve
Check outer vent valve
Rough idle or stalls
Carburetor probiems
Idle speed incorrect
Slow jet ciogged
Idle mixture incorrect
- Fuel cut solenoid valve not open Fest idle speed setting incorrect
(Cold engine)
~ Choke valve open (Cold engine)
~ Fuel pump faulty Fuel filter clogged Fuel line clogged
Fuel line bent or kinked
Adjust idle speed
Adjust idle mixture
Check fuel cut solenoid valve
Adjust fast idle speed
Check choke system
Engine hesitates/poor acceleration
Carburetor problems
Float level too low
- Accelerator pump faulty Power valve faulty Power piston faulty
Choke valve closed (hot engine)
Choke valve stuck open
(cold engine)
Adjust float level
Check power valve Check power piston Check choke system
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Problem
Possible cause
Remedy Page
Engine hesitateslpoor acceleration
Fuel line clogged
- Fuel pump faulty
Fuel filter clogged
Fuel line bent or kinked
Check fuel line
Check fuel pump
Replace fuel filter
Replace fual line
Engine dieseling (Runs after ignition switch is turned off)
Carburetor problems
- Linkage stiking
Idle speed out of adjustment
Fuel cut solenoid faulty
FU-3
Adjust idle speed MA-9 Check fuel cut solenoid valve FU-5, FU-17
Poor fuel mileage
Carburetor problems
- Choke falty
Idle speed too high
Power valve always open
ldle mixture incorrect
Fuel leak
Check choke system
Adjust idle speed Check power piston and valve
Adjust idle mixture
Repair as necessary
Unpleasent odor
Outer vent valve always open
Check outer vent valve FU-5, FU-17
nove the following hoses: Vacuum hose to BVSV gli 0 ITC vacuum hose to carburetor “U I 0 PCV gas hose wmmw
(1) Remove the following hoses:
0 Vacuum hose to BVSV
0 Hot air intake hose 0 Cool air intake hose (2) Remove the air cleaner.
2. Inspection of carburetor and linkage
(2) Check each linkage for evidence of excessive wear
Also, check to see if any snap ring is missing
(1) Ensure that each screw plug is installed correctly. (2) Check each linkage for evidence ot excessive wear. Also, check to see if any snap ring is missing. . (3) With the acceleration pedal fully depressed, check to
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see if the throttle valve opens fully.
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Inspection of choke system
cold
Check that choke valve is completely closed when engine is cold. ff Then, start the engine, chek that choke valve is gradually _f fl? - opened in accordance with the warning-up condition of the if .il 1*' cl
Inspection of solenoid valve
(1) Check to see if you can feel the operation of the solenoid
valve when the ignition switch is turned ON/OFF. If the solenoid valve remains inoperative, check the power supply for the solenoid valve. Then, proceed to the check described in the step (2) below.
(2) Disconnect the connector from the carburetor. Check to see if the resistance between the solenoid valve terminal and the carburetor proper conforms to the specification. specified Resistance: so - won at 20°C If the resistance fails to conform to the specification, replace the solenoid valve.
(3) Reconnect the connector.
FU-4
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6. Inspection of outer vent valve
J- 7 (1) Check to see if you can feel the operation of the outer 4 'l
vent valve when the ignition switch is turned ON/OFF. g If the outer vent valve remains inoperative, check the
vent valve when _the ignition switchis turned ON/OFF. » ( If the outer vent valve remains inoperative, check the .
I
power supply for the outer vent valve. Then, proceed to ;/11 uw the check described in the step (2) below. (ly
, 1 f'
r _
(2) Disconnect the connector from the carburetor. Check to
see if the resistance between the outer vent valve ter- "
minal and the carburetor proper conforms to the specification. Specified Resistance: 30 - 409 at 20°C (63°F) 'X ; ) A I
(3) Reconnect the outer vent valve connector. (4) Disconnect the outer vent hose from the BVSV. Turn ON
the ignition key switch.
(5) Blow air from the outer vent hose. Ensure that no air con
tinuity exists. lf air continuity exists, replace the outer vent valve. WARNING: '17
(6) Turn OFF the ignition key switch. (7) Blow air from the outer vent hose. Ensure that air con
tinuity exists. If no air continuity exists, replace the outer vent valve. WARNING: /
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(8) Connect the outer vent hose to the
7. Inspection of choke braker
(See page FU-.4, MA-5)
8
. Inspection of throttle positioner
page MA-10)
gi
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POWER VALVE
POWER PISTON
CHOKE BREAKER
SCREW
,J SECONDARY
THROTTLE vALvE
PRIMARY
THROTTLE VALVE
SECONDARY SLOW PORT SECONDARY DIAPHHAC-`-M
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COMPONENTS
% Hose No. 2
Clip
Washer g Gasket Bolt Hose Gasket
Outer vent valve Gr Bolt Washer Union nipple g Vacuum hose No. 2
Spring
Power piston ® Needle valve
Flcat lever pin Float assembly Pump plunger
Venturi gasket No. 2 6* Main jet Main jet gasket Bon
Boot 03 Positioner 2nd main jet 2nd main jet gasket Main passage plug Main passage plug gasket solenoid valve O ring
Gasket Q; Solenoid valve gasket Venturi gasket Throttle adjusting screw Spring
@ Vacuum hose Screw Throttle adjusting spring Diaphragm hosing set screw Snap ring No. 1 Diaphragm sub assembly ldie mixture adjusting screw g Idle adjusting spring
Washer Washer Body flange gasket £1) Adjusting screw
Adjusting screw spring ‘Iv Throttle lever set screw Lock washer Return spring g Set screw Set screw ® Diaphragm
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REMOVAL OF CARBURETOR
1. Disconnect the ground cable terminal from the negative (-)
terminal of the battery. 2. Drain the coolant. (See page CO-3)
(2) Remove the air cleaner.
4. Disconnect the accelerator cable from the carburetor.
3. Removal of air cleaner 0 0
4) Cool air intake hose 5) Hot air intake hcse
Fuel inlet hose ITC vacuum hose
5. Remove the following hoses from the carburetor:
CD Fuel inlet hose
PCV gas hose Choke braker vacuum hose Vacuum hoses to gas filter Outer vent hose
Throttle positioner vacuum hose Vacuum hose to distributor Coolant circulating hoses
Di
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6. Disconnect the solenoid valve outer vent valve connector. . Remove the four attaching nuts of the carburetor. Hemove N the carburetor.
6. Disconnect the solenoid valve outer vent valve connector. i *A 4 7. Remove the four attaching nuts of the carburetor. Remove of
PQ/
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DISASSEMBLY OF CARBURETOR
NOTE: The following operations have been arranged in such a way that cheeks are performed for a certain single unit alone at a time. This will avoid any occurrence of wrong assembling of similar subassemblies which would likely occur when opera- tions were carried out concurrently. (1) Be sure to arrange the disassembled parts in order that
reassembling may be performed readily. (2) Do not mix up those balls, clips, springs and so forth. (3) Be sure to employ the following SST, a set of
screwdrivers for carburetor use.
Do net disassemble the following sections.
Choke valve set screw Throttle valve set screw Automatic choke mechanism Small venturis Fast idle adjust screw Acceleration lever, link connecting nut
(2) Remove the idle-up actuater for power steering. (only for
power steering equipped vehicle) j
