Golf L4-1781cc 1.8L SOHC (ACC) Can (1993)
Fuel Pressure Regulator: Testing and Inspection
Fuel Pressure Regulator and residual pressure, checking
^ Fuel pump delivery quantity OK
WARNING!
Fire Hazard! To prevent fuel spray when loosening connecting points, place rags around respective connection.
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Connect VAG 1318 pressure tester to measuring port using VAG 1318/11 and VAG 1318/23 adapters as shown.
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Open gauge valve (lever in direction of flow).
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Start engine and let idle.
If engine does not start:
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Remove Fuel Pump (FP) Relay (J17) from fuse/relay panel (position 12).
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Connect VAG 1348/3A remote switch between terminal -4- on fuse/relay plate and Battery Positive Voltage (B+) using VAG 1348/3-2 adapter
cable.
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Operate remote switch and measure fuel pressure
^ Specified value: approx. 0.8-1.2 bar (11.6-17.4 psi)
If measured pressure value is too low:
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Replace upper section of Throttle Body.
If measured pressure value is too high:
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Check return line for blockage, replace upper section of Throttle Body if necessary.
Residual pressure, checking
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Switch ignition or remote switch OFF and check residual pressure.
^ At least 0.5 bar (7.25 psi) after 5 minutes
If residual pressure drops lower than spec, check the following:
^ Fuel line connections leaking
^ Fuel pump check valve NOT OK
^ Fuel Injector O-rings leaking
^ Fuel Injector leaking
^ Fuel pressure regulator NOT OK
Note: The upper section of the Throttle Body and the fuel pressure regulator are matched parts. If the pressure regulator is replaced, also replace
the upper section of the Throttle Body.