G420E/G424E Tier LP Engine Basic Troubleshooting 43
Problem Probable Cause Corrective Action
Air/Fuel Mixer malfunction Check mixer
z See Chapter 8 Air/Fuel mixer section
Air filter clogged Check air filter
z Clean/replace as required
Vacuum leak Check system vacuum hoses from regulator
to FTV and mixer
z Repair/replace as necessary
Pressure regulator malfunction/fuel
pressure too high
Test pressure regulator operation
z See Chapter 9 Tests and Adjustments
Faulty FTV Check FTV for housing cracks or obstructions
z See Chapter 5 Advanced Diagnostics
FTV operation
z Repair and/or replace as necessary
Weak ignition and/or spark control See Chapter 5 Advanced Diagnostics
Incorrect air/fuel control See Chapter 5 Advanced Diagnostics
Exhaust system leaks Repair exhaust system
Excessive Fuel
Consumption/LP
G Exhaust Smell
Oxygen sensor failure Replace as necessary
z See Chapter 5 Advanced Diagnostics