Service manual

G420F(FE) Service Manual Chapter 2. Recommended Maintenance 29
Testing Fuel Lock-off Operation
• Start engine.
• Locate the electrical connector for the fuel lock (A).
• Disconnect the electrical connector.
• The engine should run out of fuel and stop within a
short period of time.
NOTE
The length of time the engine runs on trapped fuel
vapor increases with any increase in distance
between the fuel lock-off and the pressure
regulator/converter.
• Turn the ignition key switch off and re-connect the
fuel lock-off connector.
Pressure Regulator/Converter
Inspection
• Visually inspect the pressure regulator/converter
(B) housing for coolant leaks.
• Refer to Chapter 5 if the pressure
regulator/converter requires replacement.
Fuel Trim Valve Inspection (FTV)
• Visually inspect the fuel trim valves (C) for
abrasions or cracking. Replace as necessary.
• To ensure a valve is not leaking a blow-by test can
be performed.
1. With the engine off, disconnect the electrical
connector to the FTVs.
2. Disconnect the vacuum line from the FTVs to the
pressure regulator/converter at the converter’s
tee connection.
3. Lightly blow through the vacuum line connected to
the FTVs.
Air should not pass through the FTVs when de-
energized.