Joyner JNSZ1600QL, Owner'S Manual

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124
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When engine is idling with no electrical load and
λ
controlling is functioning(close loop)
，
select
LAMBDA CHECK to check if the slipping ruler on the CHEC K—UP1 diagnosis tool is in the middle of
two base points .
7. Catalytic converter
Fig.177
Exhaust emission is controlled by
λ
sensor and the above relative systems and three-way catalytic converter.
Catalytic converter may damp the three contaminations in the exhaust: unburned hydrocarbon (HC), carbon
monoxide (CO) and nitrogen oxide (NOX).
Two kinds of complicated chemical reactions exist in the catalytic converter: the oxidation of carbon
monoxide and hydrocarbon changing into carbon dioxide and water; nitrogen oxide changing into nitrogen.
note
：
Using leaded gasoline may damage the catalytic converter and weaken its catalytic capability so
that it does not function completely for the system. And the damage is irremediable. The weakening of the
catalytic converter capability for the chemical reaction should not occur within 80 thousand kilometers or
five years.
Besides lead, the unburned fuel in the converter is another factor for the catalytic converter failure.
In the catalytic converter, the temperature is 800
℃
. Even so
，
if fuel only remains in the converter for
30 seconds , the combustion caused by the fuel will damage the converter .sometimes, a few-second stay of
the fuel in the converter may result in irremediable damage. Therefore, it is very necessary to insure the
ignition system high performance.
During repairing and testing, be sure to avoid unplugging the spark wire when engine is operating. If it
is needed to do this kind of test, it is suggested to replace the converter temporarily with a pipe and perform
the test.
The fuel tank ventilation style applied on the system is “close loop”type. It prevents the vapor coming
from the fuel tank and fuel supply system from emitting into the atmosphere. Thus the small quantity of
carbon compound in the fuel vapor is prevented from emitting and polluting the atmosphere.
The operation during engine doesn’t run