9000 L4-2290cc 2.3L DOHC Turbo EFI (1992)
Fuel Pressure Pulsation Damper: Customer Interest
Fuel System - Tapping/Knocking Noise
CATEGORY
Engine
SECTION
2
PAGE
13
ISSUE
10/91-0145
CODE
241
Subject:
Fuel Pulsation Noise
Application:
M9O- 9000 Models with B234 Engine
Some 1990- 9000 vehicles equipped with the 2.3 liter engine may develop a pulsation noise that can be heard inside the car. Customer complaints often
refer to a tapping or knocking sound that is heard when the car is idling at a stop.
The most likely cause of this noise is a faulty fuel line damper, located between the fuel supply line and the distribution rail on the engine. The function
of this damper is to reduce the fuel pressure waves that are generated in the supply line by the simultaneous opening and closing of all four injectors. All
cars have the noise to some degree, but it may be objectionable to some customers, particularly if the diaphragm within the damper is damaged.
A new damper, P/N 41 64 232, containing a spring-loaded diaphragm has been developed for use as a service measure. A modified version of this
damper will also be introduced as a running change during mid-1992 production.
Parts required:
Damper
P/N 41 64 232
Seal rings (2 required)
P/N 89 81 979
Repair procedure:
1.
Disconnect the negative cable from the battery.
WARNING!
Always observe the following safety precautions when working on the fuel system
^
No Smoking!
^
Have A Fire Extinguisher Nearby.
