fuel filter TOYOTA CAMRY 2000 Service Repair Manual

3
CAMRY ± NEW FEATURES
172CM14
Fuel
Pressure
SensorFuel Temp.
SensorFuel
Pressure
RegulatorFuel Shutoff ValveFuel Tank
Fuel Shutoff ValveRelief Valve
Inlet Check
Valve
Fuel Temp.
Sensor
Coupler
Tank Valve Assembly
Vent Tube Manual
Shutoff
Valve Oil
Separator
Fuel Shutoff Valve Injectors
Delivery Pipe Discharge
ValveFuel
Pressure
SensorFuel
Filter43
6. Fuel System
General
The compressed gas [maximum pressure approximately 250 kg / cm
2 (3600 psi, 24.8 MPa) @ 21C
(70F)] from the CNG fuel tank located in the rear section of the vehicle is routed via a fuel filter to the
engine compartment. The pressure of the fuel is then reduced to 8 kg / cm
2 (114 psi, 785 kPa).
A pressure regulator and injectors designed exclusively for CNG application have been adopted.
A fuel pressure sensor and a fuel temperature sensor that are used for the correction of the fuel injection
volume are located on the delivery pipe.
The fuel tank, pressure regulator, and the delivery pipe are provided with shutoff valves that shut off the
fuel when the ignition switch is turned OFF.
In addition, these valves shut off the fuel when the engine stalls, the SRS airbag is deployed, or the pres-
sure in the main pipe becomes abnormally low.
A fuel temperature sensor for the fuel gauge is mounted on the tank valve assembly, and a fuel pressure
sensor is mounted immediately upstream of the pressure regulator.

Fuel System Diagram 

CAMRY ± NEW FEATURES
167CN10
172CM15
Fuel
Shutoff
Valve
Water Passage
Oil SeparatorRelief Valve 46
Fuel Filter
Mounted below the vehicle floor, the fuel filter
removes any moisture or oil from the fuel.
Fuel Pressure Regulator
The fuel pressure regulator regulates the fuel pressure by reducing the pressure of the compressed natural
gas from the fuel tank to the fuel injection pressure, which is 8 kg / cm
2 (114 psi, 785 kPa).
Similar to the fuel shutoff valve for the fuel tank, a fuel shutoff valve is provided on the fuel inlet side
of the fuel pressure regulator to shut off the supply of fuel when the engine is stopped or during abnormal
conditions.
An oil separator that traps the moisture and oil in the fuel is provided on the low pressure side.
A built-in relief valve is provided to protect the parts located on the low pressure side.
While the fuel pressure is being reduced by the fuel pressure regulator, the Joule-Thomson effect
associated with the expansion of the gas causes the fuel pressure regulator to be cooled excessively, exert-
ing unfavorable influence on the rubber parts such as diaphragms and fuel hoses.
Therefore, to raise the gas temperature, a water passage is provided in the fuel pressure regulator to allow
the engine coolant to warm the regulator.

CAMRY ± NEW FEATURES
167CN11
Intake Air
Temp. SensorSpeedometerFuel Gage & Warning
MIL
DLC3
Airbag Sensor Assembly
ECM
VSV
(for EGR)
EGR Vacuum
ModulatorIAC Valve
Throttle
Position
Sensor
Fuel Temp.
Sensor
Fuel Shutoff
ValveFuel
Pressure
Regulator
Oil
SeparatorFuel
Shutoff
Valve
Fuel
Pressure
Sensor
EGR Valve
Crankshaft Position
Sensor Manifold
Absolute
Pressure
SensorFuel Pressure
Sensor
Engine Coolant
Temp. Sensor
Camshaft
Position
Sensor
Air Fuel
Ratio Sensor
WU-TWC
Heated Oxygen Sensor
TWCManual Fuel
Shutoff
ValveFuel Filter
Fuel TankFuel Temp. Sensor
Fuel Shutoff Valve
Coupler 52
Engine Control System Diagram

Troubleshooting
If the CO/HC concentration does not comply with
regulations, perform troubleshooting in the order
given below.
(a) Check oxygen sensor operation.
(See page EG1±231)
(b) See the table below for possible causes, then inspect
and correct the applicable causes if necessary.
1. Faulty ignitions:
wIncorrect timing
wFouled, shorted or improperly gapped plugs
wOpen or crossed high±tension cords
wCracked distributor cap
2. Incorrect valve clearance
3. Leaky EGR valve
4. Leaky intake and exhaust valves
5. Leaky cylinder
1. Restricted air filter
2. Faulty MFI/SFI systems
wFaulty pressure regulator
wClogged fuel return line
wDefective engine coolant temp. sensor
wDefective intake air temp. sensor
wFaulty ECM
wFaulty injector
wFaulty throttle position sensor
wMAP sensor 1. Vacuum leaks:
wPCV hose
wEGR valve
wIntake manifold
wThrottle body
w!AC valve
wBrake booster line
2. Lean mixture causing misfire
Rough idle
(Black smoke from exhaust) Rough idle
(Fluctuating HC reading) Rough idleProblems
Causes
Normal
High High High
HighLow
± 5S±FE ENGINEENGINE MECHANICALEG1±22

(c) Disconnect the following connectors:
(1) Igniter connector
(2) California only:
Ignition coil connector
(3) Noise filter connector
(4) 2 ground straps from LH fender apron
(5) Connector from LH fender apron 12. DISCONNECT WIRES AND CONNECTORS
(a) Remove the engine relay box, and disconnect the 5
connectors.
(b) Connector from LH fender apron
(6) Data link connector 1
(7) 2 ground straps from RH fender apron
(d) Disconnect the MAP sensor connector.
13. DISCONNECT HEATER HOSES
14. DISCONNECT FUEL RETURN HOSE
CAUTION: Catch leaking fuel in a container.
± 5S±FE ENGINEENGINE MECHANICALEG1±86

(d) Connect the following connectors:
(1) Igniter connector
(2) California only:
Ignition coil connector
(3) Noise filter connector
(4) 2 ground straps from LH fender apron
(5) Connector from LH fender apron 24. CONNECT WIRES AND CONNECTORS
(a) Connect the 5 connectors to the relay box.
(b) Connectors from LH fender apron.
(c) Install the engine relay box. 21. CONNECT FUEL INLET HOSE
Torque: 29 N±m (300 kgf±cm, 22 ft±lbf)
22. CONNECT FUEL RETURN HOSE
23. CONNECT HEATER HOSES
± 5S±FE ENGINEENGINE MECHANICALEG1±132

No. 1 balance shaft housing x No. 2 balance shaft housing (1st)
No. 1 balance shaft housing x No. 2 balance shaft housing (2nd)
FR engine mounting insulator x Front suspension member
RR engine mounting insulator x Front suspension member Exhaust manifold stay x FR engine mounting insulator No. 1 air intake chamber stay x Intake manifold
RR engine mounting insulator x Cylinder block
FR engine mounting insulator x Cylinder block No. 1 air intake chamber stay x Cylinder head
No. 1 exhaust manifold stay x Cylinder block
Connecting rod cap x Connecting rod (2nd) Connecting rod cap x Connecting rod (1 st)
LH engine mounting insulator x Transaxle No. 1 exhaust manifold stay x WU ±TWC Water bypass pipe x Water pump cover
Fuel inlet hose x Fuel filter (Union bolt) No. 3 timing belt cover x Cylinder head
Intake manifold stay x Intake manifoldCamshaft bearing cap x Cylinder head
Intake manifold stay x Cylinder blockCylinder head x Cylinder block (2nd)
Rear oil seal retainer x Cylinder block Exhaust manifold stay x WU ±TWC
PS pump bracket x Cylinder block Main bearing cap x Cylinder block Generator bracket x Cylinder head
A/C compressor x Cylinder block Pulsation damper x Delivery pipe
Exhaust manifold x Cylinder head
Engine balancer x Cylinder block
Front exhaust pipe x WU ±TWC Spark plug tube x Cylinder head
Rear end plate x Cylinder block Throttle body x Intake manifold Intake manifold x Cylinder heedEngine hanger x Cylinder head
Drive plate x Crankshaft (A/T)Knock sensor x Cylinder block Delivery pipe x Cylinder head
PS pump x PS pump bracketWU±TWC x Exhaust manifold
Flywheel x Crankshaft (M/T) Water outlet x Cylinder headEGR valve x intake manifold
EGR pipe x Cylinder head
± 5S±FE ENGINEENGINE MECHANICALEG1±144

3. CHECK FOR CLOGGED FILTER AND STUCK CHECK
VALVE
(a) Using low pressure compressed air (4.71 kPa, 48
gf/cm
2, 0.68 psi), blow into port A and check that air
flows without resistance from the other ports.
(b) Blow air (4.71 kPa, 48 gf/cm
, 0.68 psi) into port B
and check that air does not flow from the other ports.
If a problem is found, replace the charcoal canister.
4. CLEAN FILTER IN CANISTER
Clean the filter by blowing 294 kPa (3 kgf/cm
, 43 psi)
of compressed air into port A while holding port B
closed.
NOTICE:
wDo not attempt to wash the canister.
wNo activated carbon should come out.
5. REINSTALL CHARCOAL CANISTER
FUEL VAPOR LINES. FUEL TANK AND
TANK CAP INSPECTION
1. VISUALLY INSPECT LINES AND CONNECTIONS
Look for loosen connections, sharp bends or damage.
2. VISUALLY INSPECT FUEL TANK
Look for deformation, cracks or fuel leakage.
CHARCOAL CANISTER INSPECTION
1. REMOVE CHARCOAL CANISTER
2. VISUALLY INSPECT CHARCOAL CANISTER
Look for cracks or damage. 3. VISUALLY INSPECT FUEL TANK CAP
Check if the cap and/or gasket are deformed or dam±
aged.
If necessary, repair or replace the cap.
± 5S±FE ENGINEEMISSION CONTROL SYSTEMSEG1±150

Fuel pumped up by the fuel pump, flows through the fuel filter and is distributed to each injector
at a set pressure maintained by the pressure regulator.
The fuel pressure regulator adjusts the pressure of the fuel from the fuel line (high pressure side)
to a pressure 284 kPa (2.9 kgf/cm
, 41 psi) higher than the pressure inside the cylinder head, and
excess fuel is returned to the fuel tank through the return pipe.
The pulsation damper absorbs the slight fluctuations in fuel pressure caused by fuel injector from
the injector.
The injectors operate on input of injection signals from the ECM and inject fuel into the cylinder
head.
OPERATION
FUEL SYSTEM
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±167

2. CHECK FUEL PRESSURE
(a) Check that the battery voltages is above 12 volts.
(b) Disconnect the negative (±) terminal cable from the
battery.
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the ªLOCKº
position and the negative (±) terminal cable is discon±
nected from the battery.
If there is no pressure, check the following parts:
wFusible link
wFuses (AM2 30A, EFI 15A, IGN 7.5A)
wEFI main relay
wFuel pump
wWiring connections (c) Check that there is pressure in the hose from the fuel
filter.
HINT: At this time, you will hear fuel return noise.
(e) Remove the SST.
SST 09843±18020 (d) Turn the ignition switch OFF.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±178