Cessna T188C - Page 225

MODEL 188 & T188 SERIES SERVICE MANUAL
11B-34.
FUEL
INJECTION
PUMP.
11B-37.
INSTALLATION.
a. Position
a new gasket
and fuel pump
on the
11B-35.
DESCRIPTION.
The fuel pump
is a positive
mounting
studs with fuel pump
inlet to the
left. Be
displacement. rotating
vane type. It has a splined
sure pump drive aligns
with drive in the engine.
shaft for connection to the accessory drive section of b. Secure pump to engine with plain washers. in-
the engine.
Fuel enters the pump at the
swirl well of ternal tooth
lockwashers and nuts. Tighten
nuts
the
pump vapor
separator.
Here, vapor
is separated
evenly.
by a swirling
motion so that
only liquid fuel
is fed to
c. Install
cooling shroud
on fuel pump.
the
pump. The vapor is drawn
from the top center of
d. Install all fittings and connect
all lines.
the swirl well
by a small pressure
jet of fuel
and is
e. Install the flexible
ram air
tube on the air
horn
fed into the vapor return
line where it is returned
to of the fuel pump
shroud and install clamp.
the fuel tank. Since the pump
is engine-driven.
f. Replace the alternator drive
belt and tighten the
changes
in engine speed affect total
pump flow propor- nuts
on the adjusting arm so that the
drive belt has
tionally.
A check valve allows the
auxiliary fuel pump proper
tension. Refer to Section
16.
pressure
to bypass the engine-driven
pump for start-
g. Inspect complete
installation.
ing, or in the event of engine-driven fuel pump failure
in flight.
The pump supplies more
fuel than is re- 11B-38.
ADJUSTMENT. Adjustments
of the fuel in-
quired by the engine; therefore,
a relief valve is pro-
jection pump requires special
equipment and proce-
vided
to maintain a constant fuel pump
pressure. The dures.
Adjustment to the aneroid applies
only to the
engine-driven fuel
pump is equipped with an aneroid.
full throttle setting.
Adjustment of the idle position
The aneroid and relief
valve are pressurized from the
is obtained through the
relief valve. To adjust the
discharge side of
the turbocharger compressor
to pump to the pressures
specified in paragraph 11B-8,
maintain
a proper fuel/air ratio
at altitude. The
proceed as follows:
aneroid
is adjustable for fuel pump
outlet pressure at a. Remove
engine cowling in accordance
with para-
full throttle and the relief valve is adjustable for fuel graph lIB-3.
pump outlet
pressure at idle.
b. Disconnect
the existing engine-driven
fuel
pump
pressure hose
at the fuel metering
unit and
connect
11B-36.
REMOVAL.
the test
gage pressure hose and fittings
into the fuel
a. Place
full shut-off valve in OFF position
and injection system
as shown in figure 11B-1.
Gage
mixture
control in IDLE CUT-OFF
position.
MUST be vented to
atmosphere.
b. Remove
upper cowling
section in accordance
with paragraph 11B-3.
NOTE
c. Loosen
the clamps
and slide the
flexible tubes
free of the horns on
the fuel pump shroud to gain ac-
Cessna Service
Kit No. SK320-2J provides
cess
to the fuel
lines.
a test gage,
line and fittings
for connecting
d. Remove
the alternator drive belt.
the
test gage into the system to
perform
e.
Tag and disconnect
all lines
and fittings
attached
accurate calibration
of the
engine-driven
to the
fuel pump.
fuel
pump.
NOTE
c. The test gage MUST
be held as near to the
level
of the engine driven fuel pump as possible. Bleed air
Plug or cap all disconnected
lines, hoses
from test gage line
prior to taking readings.
and fittings.
NOTE
f. Remove the
shroud surrounding
the fuel
pump.
g. Remove the nuts
and washers attaching the fuel
The test gage should
be checked for accuracy
pump to the engine
at least every 90 days or
anytime an error is
h. Remove
fuel pump and gasket.
suspected.
The tachometer accuracy
should
WARNING
justments
to the pump.
Residual uel
draining from lines
and hose
d.
Start engine and
warm-up thoroughly.
Set
mix-
constitutes
a fire
hazard. Use caution
to
ture control
to full rich
position and propeller
control
prevent accumulation of
fuel when lines or
full forward (low
pitch, high rpm).
hoses are
disconnected.
e. Adjust engine
idle speed
to 600 ± 25 rpm
and
check
test
gage
for
5. 5
- 6. 5
PSI.
i. If a
replacement
pump is
not being
installed
im- check
test
gage for
5.5 - 6.5
PSI.
mediately, a temporary cover should be installed on NOTE
the fuel pump mount pad.
Do not adjust idle mixture until idle pump
pressure is obtained.
11B-11