Piper COMANCHE PA-24-180 Service Manual page 514

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PIPER COMANCHE SERVICE MANUAL
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FIGURE 8-17. EXPLOOED VIEW BENOIX ROTARY FUEL PUMP
8-29. Fuel Pump Prssure Check.
1. Carbureror Induction Sysem.
L
The engine driven pump and the elecric pump(s) may be checked by using the pressure gage
in the instrument panel or connecting a gage to the inlet of the carburetor.
b.
Check the operation of the engine driven pump with the engine operanng from low rhru high
rpm and the electric pump off.
c.
The electric fuel pump pressure may be checked with the engine shut down and the electric
pump on.
d.
A pressure reading for engine driven and electric pumps on the 0-360 and 0-540 engines
should nor be under 0.5 pounds nor over 6 pounds. with a desired pressure of 3 pounds.
2. Fuel Injection System.
a.
Fuel pressures of the engine driven pump and electric pump may be taken bv connecting a
pressure gage to the fuel line. at the inlet o the engine driven pump and at the inlet to the injector.
operating the engine and obseving the pressure readings as given in Table VIII-l. The electric fuel pump
must be operated it approximately 14 volts, therefore with the engine operating at idle. assistance of one
cell from another batterv connected in series may be necessary to bring the voltage uo to 14 volts.
FUEL SYSTEM
ISSUED: 8/18/72
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