Mazda 323 1988 Workshop Manual page 334

4B
TURBOCHARCING SYSTEM
INSPECTION
Turbocharger Boost Pressure
1, Disconnect the air hose to the waste gate valve.
2. Connect a pressure gauge as shown.
3. Connect a tachometer to the engine.
4. Warm up the engine to operating temperature.
5.
Increase the engine speed to 4,000
rpm
and
check that the boost pressure is within the specifi-
cation.
Specification
Min. 2.0 kPa (0.02 kg/cm*, 0.28 psi)
6. If not within specification, check the turbocharger.
Turbocharger
Inspection of wheel assembly
1. Cool the engine.
2. Remove the air hose.
3. Check that the rotor assembly turns smoothly.
4. If there is excessive load or noise, replace the tur-
bocharger.
Inspection of wheel deflection
1. Cool the engine.
2. Remove the air hose.
3. Check if the wheel touches the compressor
housing.
4. If the wheel touches the housing, replace the tur-
bocharger.
Inspection of Oil Passage
1. Cool the engine.
2. Remove the oil return pipe.
3. Check that carbonized oil has not blocked the oil
passage in the turbocharger or the oil return pipe.
4. If carbonized oil blocks the oil passage, replace
the turbocharger, and return pipe if necessary.
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