1999 TOYOTA CAMRY CNG engine

104
If you smell or hear natural gas
leaking, shut off the fuel system
immediately. If leaking fuel is ig-
nited, an explosion or fire could oc-
cur, causing death or serious injury.
NOTICE
Do not use improper fuel that does
not meet the required standards.
Using improper fuel may affect the
engine performance or cause dam-
age to the emission control system.
If you suspect any abnormality in
the fuel system, have your vehicle
inspected by your authorized Toyota
CNG dealer as soon as possible.
1. Fuel tank
2. Manual shut off valve
Have the fuel system checked and main-
tained by your authorized Toyota CNG
dealer.
—Fuel tank
The fuel tank on your vehicle conforms
to ANSI/AGA NGV−2, NFPA−52 and DOT
NHTSA FMVSS 304 safety standards.
Removal, servicing, discharge of fuel
and disposal of the tank should only be
done by a qualified technician as pre-
scribed by the fuel control regulation of
NFPA−52, and all applicable federal,
state and local regulations.
Have the fuel tank inspected at the
interval listed in the “Scheduled
Maintenance Guide”. The fuel tank also
requires inspection if the vehicle is
involved in a collision or fire hazard.
Warning labels on the fuel tank and the
engine compartment indicate the ser-
vice limit date of the tank. Do not re-
move or paint over the labels.
See instructions on fuel
container for inspection
and service life.
Fuel system—
—Components

105
CAUTION
This tank contains high pressure
flammable natural gas. You must
ensure that the tank is checked and
inspected and properly maintained,
as well as avoid overfilling or dril-
ling holes in it, or damaging it in
any other way because death or se-
rious injury may result.
Do not allow any person other than
a qualified technician to remove
this tank from the vehicle. If residu-
al gas in the tank is not discharged
correctly, static electricity may be
ignited, causing fire or explosion.
Do not leave the fuel tank where
the temperature can exceed 80C
(176F). The tank’s built−in pressure
relief device may open and release
all the fuel from under the floor.
NOTICE
Do not damage the tank. If the tank
is damaged, have it inspected by
your authorized Toyota CNG dealer
as soon as possible.
Do not expose the tank to chlorine,
oxygen or other corrosive liquids.
This tank is intended for use with
compressed natural gas—the fuel
for this vehicle. Do not use it for
any other purpose.
SERVICE PRESSURE:
24800 kPa (3600 psig)
Equivalent gasoline capacity:
43 L (11.4 gal., 9.5 lmp.gal.)
Water volume:
135 L (35.7 gal., 29.7 lmp.gal.)
—Fuel shut off system
If the engine stalls, fuel flow from the tank
is automatically shut off. When restarting
the engine after fuel flow is shut off, turn
the ignition switch to “ACC” or “LOCK”
once and then start it. The fuel flow from
the tank will also be shut off automatically
when an airbag inflates upon collision or
if the piping is disconnected.
CAUTION
If the vehicle is involved in a colli-
sion and there is a chance that there
may be fuel leakage, never restart the
engine. Ignition of leaked natural gas
may cause death or serious injury.
Manual shut off valve
This valve is for manually shutting off
fuel from the tank. It is usually left
open. Use this valve to shut off fuel if
you suspect that the fuel is leaking or
after you have been involved in a colli-
sion.
Refer to “If you suspect the fuel is
leaking” in Part 4 for how to operate the
valve.

106
Operation in foreign countries
If you plan to drive your Toyota in
another country...
First, comply with the vehicle registration
laws.
Second, confirm the availability of the cor-
rect fuel and filling nozzles.
Three−way catalytic converter
The three−way catalytic converter is an
emission control device installed in the
exhaust system.
The purpose is to reduce pollutants in the
exhaust gas.
CAUTION
Keep people and combustible mate-
rials away from the exhaust pipe
while the engine is running. The
exhaust gas is very hot.
Do not drive, idle or park your ve-
hicle over anything that might burn
easily such as grass, leaves, paper
or rags.

107
NOTICE
A large amount of unburned gases
flowing into the three−way catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only CNG (Compressed Natural
Gas).
Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three−
way catalytic converter.
Do not allow the engine to run at
idle speed for more than 20 min-
utes.
Avoid racing the engine.
Do not push−start or pull−start your
vehicle.
Do not turn off the ignition while
the vehicle is moving.
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel system could cause an ex-
tremely high three−way catalytic
converter temperature.
If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a check−up as soon
as possible. Remember, your autho-
rized Toyota CNG dealer knows
your vehicle and its three−way cata-
lytic converter system best.
To ensure that the three−way cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the separate “Owner’s
Manual Supplement”.
Engine exhaust cautions
CAUTION
Avoid inhaling the engine exhaust.
It contains carbon monoxide, which
is a colorless and odorless gas. It
can cause unconsciousness or even
death.
Make sure the exhaust system has
no holes or loose connections. The
system should be checked from
time to time. If you hit something,
or notice a change in the sound of
the exhaust, have the system
checked immediately.
Do not run the engine in a garage
or enclosed area except for the
time needed to drive the vehicle in
or out. The exhaust gases cannot
escape, making this a particularly
dangerous situation.
Do not remain for a long time in a
parked vehicle with the engine run-
ning. If it is unavoidable, however,
do so only in an unconfined area
and adjust the heating or cooling
system to force outside air into the
vehicle.

108
Keep the trunk lid closed while
driving. An open or unsealed trunk
lid may cause exhaust gases to be
drawn into the vehicle.
To allow proper operation of your
vehicle’s ventilation system, keep
the inlet grilles in front of the wind-
shield clear of snow, leaves, or oth-
er obstructions.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the trunk lid closed. Have
the cause immediately located and
corrected.
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume some engine oil during normal
engine operation. The causes of oil
consumption in a normal engine are as
follows.
Oil is used to lubricate pistons, piston
rings and cylinders. A thin film of oil
is left on the cylinder wall when a pis-
ton moves downwards in the cylinder.
High negative pressure generated when
the vehicle is decelerating sucks some
of this oil into the combustion chamber.
This oil as well as some part of the oil
film left on the cylinder wall is burned
by the high temperature combustion
gases during the combustion process.
Oil is also used to lubricate the stems
of the intake valves. Some of this oil
is sucked into the combustion chamber
together with the intake air and is
burned along with the fuel. High tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by high−speed driv-
ing and frequent acceleration and decel-
eration.
A new engine consumes more oil, since
its pistons, piston rings and cylinder walls
have not become conditioned.
When judging the amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately.
As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal amount of oil, the dipstick may not
show any drop in the oil level at all, even
after 1000 km (600 miles) or more. This
is because the oil is gradually becoming
diluted with fuel or moisture, making it
appear that the oil level has not changed.
Facts about engine oil
consumption

109
The diluting ingredients evaporate out
when the vehicle is then driven at high
speeds, as on an express way, making it
appear that oil is excessively consumed
after driving at high speeds.
IMPORTANCE OF ENGINE OIL LEVEL
CHECK
One of the most important points in prop-
er vehicle maintenance is to keep the en-
gine oil at the optimum level so that oil
function will not be impaired. Therefore, it
is essential that the oil level be checked
regularly. Toyota recommends that the oil
level be checked every time you refuel
the vehicle.
NOTICE
Failure to check the oil level regularly
could lead to serious engine trouble
due to insufficient oil.
For detailed information on oil level check,
see “Checking the engine oil level” in
Chapter 7−2.
Your engine is fitted with twin ground
electrode platinum−tipped spark plugs.
NOTICE
For your engine performance, use
only twin ground electrode platinum−
tipped spark plugs specially designed
for CNG vehicles. Spark plugs for
gasoline−engined vehicles cannot be
used for your vehicle.
Brake system
TANDEM MASTER CYLINDER BRAKE
SYSTEM
The tandem master cylinder brake system
is a hydraulic system with two separate
sub−systems. If either sub−system should
fail, the other will still work. However, the
pedal will be harder to press, and your
stopping distance will be longer. Also, the
brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a
single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses engine vacuum to
power−assist the brakes. If the engine
should quit while you are driving, you can
bring the vehicle to a stop with normal
pedal pressure. There is enough reserved
vacuum for one or two stops—but no
more!
Twin ground electrode
platinum−tipped spark plugs

11 0
CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your reserved vacu-
um.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard—much harder than nor-
mal. And your braking distance will
be longer.
ANTI−LOCK BRAKE SYSTEM
The anti−lock brake system is designed to
automatically help prevent lock−up of the
wheels during sudden braking or braking
on slippery road surfaces. This assists in
providing directional stability and steering
performance of the vehicle under these
circumstances.
The anti−lock brake system becomes op-
erative after the vehicle has accelerated
to a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerate to a speed below
approximately 5 km/h (3 mph).You may hear a sound in the engine
compartment for a few seconds when the
engine is started or just after the vehicle
is started. This means that the anti−lock
brake system is in the self check mode,
and does not indicate a malfunction.
Effective way to press the “ABS” brake
pedal: When the anti−lock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the anti−lock
brake system work for you, just hold the
brake pedal down more firmly. Do not
pump the brake in a panic stop. Pump-
ing the brake pedal makes the stopping
distance longer.
The brake pedal pulsation caused by the
anti−lock brake system may indicate haz-
ardous road surface conditions. Although
the anti−lock brake system assists in pro-
viding vehicle control, it is still important
to drive with all due care, because the
anti−lock brake system cannot overcome
the laws of physics that act on your ve-
hicle:
Braking capability is dependent on tire
friction with the road surface.
Even though the anti−lock brake sys-
tem is operating, a driver cannot main-
tain full control on certain slippery road
surfaces, when cornering at high
speeds, or in violent maneuvers.
Avoid high speeds on wet roads. The
anti−lock brake system cannot elimi-
nate the risk of hydroplaning and loss
of tire friction.
Always maintain a safe distance from the
vehicle in front of you. Compared with
vehicles not fitted with an anti−lock brake
system, your vehicle may require a longer
stopping distance in the following cases:
Driving on rough, gravel or snow−cov-
ered roads.
Driving with tire chains installed.
Driving on roads where the road sur-
face is pitted or has other differences
in surface height.

11 3
The vehicle identification number (VIN)
is the legal identifier for your vehicle.
This number is on the left top of the
instrument panel, and can be seen
through the windshield from outside.
This is the primary identification number
for your Toyota. It is used in registering
the ownership of your vehicle.The vehicle identification number (VIN) is
also on the Certification Label.
—Engine number
The engine number is stamped on the
engine block as shown.
—Vehicle identification
number