190E 2.3 (201.024) L4-2.3L (102.961) (1984)
Pressure measuring device = open valve screw.
b) Lower chamber pressure
Pressure measuring device = close valve screw.
Testing
The test of the system and of the lower chamber pressure must be performed with the engine running.
Place pressure measuring device on cylinder head cover.
a) System pressure when engine cold or at normal operating temperature
1 Engine at idle.
2 Take reading of system pressure.
Specification: 5.3-5.5 bar pressure
3 If the specified value is not reached or is exceeded:
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Test fuel pump. See: Fuel Delivery and Air Induction/Fuel Pump/Testing and Inspection
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Replace diaphragm pressure regulator.
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Check that fuel return line is not blocked.
b) Lower chamber pressure with engine at normal operating temperature
4 Take reading of lower chamber pressure.
Specified pressure at operating temperature approx. 0.4 bar below system pressure.
If the specified values are not reached:
-
Test electro-hydraulic actuator. Refer to "Testing Electrical Components of CFI System". See: Fuel Delivery and Air Induction/Testing
and Inspection
c) Deceleration shut-off
Engine at normal operating temperature.
5 Valve screw closed.
6 Run engine at idle speed. Briefly increase engine speed to approx. 3500/mm. As the engine speed drops, the pressure in the lower chamber
must rise to system pressure.
Combustion is restored at approx. 1200 - 1600/min.
If the specified value is not reached:
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Test microswitch. Refer to "Testing Electrical Components of CFI System". See: Fuel Delivery and Air Induction/Testing and Inspection
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Test current at actuator. Refer to "Testing Electrical Components of CFI System". See: Fuel Delivery and Air Induction/Testing and
Inspection
Vehicles up to 09/88 and model year 1989 with cruise control:
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Test signal for cruise control operation.
d) Acceleration enrichment