G420E/G424E
Tier
LP Engine
Basic Troubleshooting
37
CHAPTER 4 MI-04 LP BASIC TROUBLESHOOTING
Basic Troubleshooting
The MI-04 systems are equipped with built-in fault diagnostics. Detected system faults can be displayed by the
Malfunction Indicator Lamp (MIL) and are covered in the Advanced Diagnostics section. Items such as fuel level,
plugged fuel lines, clogged fuel filters and malfunctioning pressure regulators may not set a fault code by the Small
Engine Control Module (SECM). Below are basic checks that should be made before referring to the Advanced
Diagnostics section, if engine or drivability problems are encountered.
Locating a problem in a propane engine is done exactly the same way as with a gasoline engine. Consider all
parts of the ignition and mechanical systems as well as the fuel system.
Problem Probable
Cause
Corrective
Action
Fuel container empty
Fill fuel container
z
Do not exceed 80% of liquid capacity
Liquid valve closed
Slowly open liquid valve
Excess flow valve closed
Reset excess flow valve
z
Close liquid valve
z
Wait for a “click” sound
z
Slowly open liquid valve
Plugged fuel line
Remove obstruction from the fuel line
z
Close liquid fuel valve
z
Using caution, disconnect the fuel line
(some propane may escape)
z
Clear obstruction with compressed air
z
Re-connect fuel line
z
Slowly open liquid fuel valve
z
Leak test
Broken Fuse - SECM
Replace Fuse for SECM
z
See Maintenance Section of Operation &
Maintenance Manual, Fuses replacement
Clogged fuel filter
Repair/replace as required
z
See Chapter 3 Fuel Filter replacement
Faulty vapor connection between
the pressure regulator/converter
and the mixer
Check connection
z
Verify no holes in hose
z
Clamps must be tight
z
Look for kinked, pinched and/or
collapsed hose
Fuel Lock-off malfunction
Repair/replace Fuel Lock-off
z
See Chapter 3 Fuel Lock-off
Pressure regulator/converter
malfunction
Test pressure regulator/converter operation
z
See Chapter 9 Tests and Adjustments
Engine Cranking
but Will Not Start
Incorrect air/fuel or ignition/spark
control
See Chapter 5 Advanced Diagnostics
