36
1973 OPEL SERVICE MANUAL
FUEL SYSTEM
ALL MODELS
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Fuel Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
Evaporation Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS:
Applicable)
MAINTENANCE AND ADJUSTMENTS:
Cleaning Fuel Pump Strainer
Evaporation Control System . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAJOR REPAIR:
Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Lines and Fuel Tank Gauge Units . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS:
Fuel System Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page No.
DESCRIPTION AND OPERATION
FUEL PUMP
The 1.9 liter engine uses a push rod type fuel pump.
The push rod is actuated by an eccentric on the
distributor shaft. The push rod is held in contact
with the eccentric at all times by a push rod spring.
Each time the push rod is on the high part of the
eccentric, the lighter diaphragm spring will push the
diaphragm to replace any fuel used in the carburetor.
The diaphragm seldom operates through a full
stroke; under normal driving conditions, the dia-
phragm moves only a few tenths of an inch.
Fuel pump pressure is determined by the compres-
sion of the diaphragm spring. Low pressure or pres-
sure leak- down generally indicates a leaky
diaphragm or check valves.
Two holes in the lower part of the fuel pump serve
to ventilate the space below the diaphragm and to
drain any fuel which may have entered. If any fuel
comes from these holes, this indicates a defective
diaphragm.
When replacing the fuel pump, make sure the asbe-
stos spacer is in place with a gasket on each side. See
Figure
1. Because of the location of the fuel pump
eccentric on the distributor shaft, the fuel pump
Figure
Installing Push Rod Type Fuel Pump
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