FAULT TRACING
Bleeding the fuel system
To ensure that the engine starts, the fuel system must
be bled on the following occasions: 1) When changing
the fine filter. 2) When draining through the drain plug.
The fault-tracing scheme below includes only those
faults which arise most often during operation.
3)
When cleaning the pre-filter. 4) When running the
Fault-tracing scheme
fuel tank empty. 5) When installing the fuel injection
pump. 6) With leakage and when working on the fuel
line. 7) When the engine has been stopped for a long
time. Bleeding is as follows: Open the bleeder screw 1
on the fine filter. See Point 68. Pump forward the fuel
with the help of a hand primer until about 0.2 litre (0.2
qt.) fuel has run out. Close the bleeder screw. If you
get poor pumping effect, turn over the engine a bit so
that the pump drive cam alters its position. If the fuel
injection pump has been removed, or when starting an
entirely new engine for the first time, the fuel injection
pump must be bled. Pump with the hand primer for
about 1/2 minute. This automatically bleeds the fuel
injection pump. Slacken the delivery pipe nuts for the
injectors and turn over the engine with the start-
generator until fuel comes from the delivery pipes.
Tighten up the delivery pipe nuts and start the engine.
FAULT
Notes
Main switch not on,
flat battery, broken
electric cables
X
X
A
B
Empty fuel tank,
closed fuel cock,
blocked fuel filter
Water, air or
X
X
X
X
X
X
X
B
C
impurities in fuel
Defective injectors
Boat abnormally
loaded. Growth on
boat bottom.
X
X
X
C.
D.
Check the injectors with regard to their opening
pressure, tightness and spray pattern. Max. running
time of 400 operating hours or once a season is
recommended between these checks. See also Points
37 and 38.
D
E
X
Damaged propeller
Clogging of cooling
water intake,
X
cooling jackets,
defective impeller
or thermostat
F
In order to get the best possible operating economy,
the engine speed selected should be minimum 300
rev/mm below the max. speed for The engine during
lengthy periods of operation. When the boat has been
in the water for so’ time, the max. speed for the engine
can drop due to growth on the outside of the hull. Use
anti-fouling paint. Check and clean the hull regularly.
A. Check the state of charge of the battery with the help
of a hydrometer which shows the specific gravity of the
battery acid. This will vary with the state of charge, see
under “Technical Data”. Also see under “Electrical
system” on page 23.
E.
F.
Check the propeller blades. If a propeller blade is
damaged, the propeller must be replaced. A propeller
blade can also be warped, something which is very
difficult to discover. Place the propeller on a flat disc
and measure the blades. If a propeller blade is
warped, the propeller should be replaced.
B. Replace the fine filter by turning the hex head in the
bottom of the container. The fine filter and container
are of the throw-away type. They must be discarded
and a new one installed. Check that the contact
surface for the cover is absolutely clean and that the
filter gasket is in good condition. Screw on the new
filter tight by hand until the gasket goes against the
cover. Then tighten the filter a further 1/2 turn. The
bottom of the filter container has a drain plug for
draining water and impurities that have accumulated in
the fuel. Bleed the fuel system after draining and
replacing the filter, also check for leakage.
Remove the feed pump cover and clean the pre-filter
in the fuel oil. Then fit the filter with the pins facing
upwards and place the gasket (undamaged) in position
and tighten up the cover. Bleed the fuel system.
Check and if necessary drain the extra fuel filter if such
is fitted. Look out for fuel splash.
Check the cooling system for leakage, clogging, etc.
Check to make sure the thermostat opens at the right
temperature. The thermostat can be removed after
having taken down the thermostat housing at the front
of the exhaust manifold. See also Point 49. The pump
body in the sea-water pump is made of neoprene
rubber, which can be damaged with shortage of water,
e.g., in the event the sea-water inlet is blocked.
Proceed according to Points 45-48 in the event the
impeller and sealing rings have to be replaced. NOTE!
If the boat is in the water, the bottom cock must be
closed before the sea-water pump is removed. But do
not forget to open the cock again.
33
| Categories | Volvo Penta Manuals |
|---|---|
| Tags | Volvo Penta MD6A, Volvo Penta MD7A |
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(2 votes, average: 3.5 out of 4)
Marine readers have rated Volvo Penta MD6A MD7A Workshop Manual 3.5 out of 4.0 based on 2 product reviews. good manual just what I needed
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