CAC Gasoline Engine Maintenance And Servicing Manual
92
to check all sensors and actuators, injection system ECU has a complete high-efficiency self-diagnosis
system. When failure occurs, the warning light will turn on.
Warning：Before checking exhaust emission orλsensor, check：
1. The warning light should go out, or use CHECK—UP1 diagnosis instrument to determine the failure
and adjust it for correct operation.
2. little difference exists between the working parameter showed on CHECK—UP1 and the actual engine
condition.
3. The fuel pressure should be the specified value (0.9—1.0bar). When the pump stops, no sudden
pressure drop occurs ( pressure sealing).
4. When the fuel pump operates, CHECK—UP1 performs to stop engine and recycle oil circuit.
Injection system ECU may adjust automatically, therefore it
may compensate for the system failure caused by the engine
degradation. According to the signal of λsensor (figure 151)，in
the precondition of without any exterior interference, the mixture
can be automatically adjusted to the perfect value electronically.
·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
Exhaust emission is controlled by λsensor and the above relative systems and three-way catalytic converter.
Fig.151 λ sensor signal
drawing 152 exhaust system
1. λ
sensor 2. catalytic converter
3. CO inspection channel, in front of
catalytic converter
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