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aprilia
Air-injection 50 cc
Release 00 / 2002 - 09
INJECTION TROUBLESHOOTING
05 / 07
Chapter.5
To discharge air from the circuit:
- switch to “ON”
- nudge the starter motor so it switches on momentarily
- the pressure of the fuel circuit should be 2.5 ± 2.0 bar
- switch off
- now the pressure gauge can be fitted
NO
Switch to “OFF”
Is the pressure 2.5 bar?
NO
(DOUBLE CHECK THE MALFUNCTION BEFORE REPLACING ANY PART)
Fit the pressure gauge to the petrol circuit, between fuel pump and fuel rail
Does the starter motor for the pump start
up? Can you hear the characteristic buzz
when you switch on?
Check the power at the pump connector. If the voltage is
correct, replace the petrol pump.
N.B. After replacing the pump, start up as specified
above (point 6 of Troubleshooting the Injection)
YES
NO
Does the pressure stay at 2.5 ± 2.0 bar?
Check:
-
the tank breather
-
the petrol filter and tank delivery flange
-
the fuel feed hose
- Start up as specified above (point 6 of
Troubleshooting the Injection)
YES
NO
Check the pump pressure blocking the
delivery hose below the pressure gauge.
Is the pressure 7 bar?
N.B. Do not exceed 7.5 bar, or the pump
will be damaged.
Replace the fuel pump
NO
Blocking the delivery hose above the pump,
does the pressure remain?
N.B. Do not exceed 7.5 bar, or the pump
will be damaged.
Check the hoses and replace the Fuel Rail if necessary
YES
YES
Does the pressure stay at
7.5 bar on “OFF”?
NO
YES
Replace the petrol pump
YES
CHECKING THE PRESSURE OF THE AIR AND FUEL CIRCUITS