Doosan D20S-5 Operation & Maintenance Manual page 98

Operation Section Operation Section
Problem Problem
Will Not Will Not
Accelerate/Hesita Accelerate/Hesita
tion During tion During
Acceleration or Acceleration or
Engine Stalls Engine Stalls
(Gas) (Gas)
Rough Idle (Gas) Rough Idle (Gas)
Probable Cause Probable Cause
Throttle butterfly valve not opening Throttle butterfly valve not opening
or sticking or sticking
Foot Pedal signal incorrect or Foot Pedal signal incorrect or
intermittent intermittent
Incorrect air/fuel or ignition control Incorrect air/fuel or ignition
Engine Engine Mechanical Mechanical
Isolate the gasoline system by Isolate the gasoline system by
running the lift truck on LPG running the lift truck on LPG
Pressure Pressure regulator regulator malfunction malfunction
Clogged Clogged fuel fuel filter filter
Pressure Pressure regulator regulator malfunction malfunction
Fuel Fuel Injector Injector malfunction malfunction
Vacuum Vacuum leak leak
-95- -95-
Corrective Action Corrective
See Advanced Diagnostics See Advanced Diagnostics
control
See Engine See Engine Service Service Manual
Verify LPG cylinder is full and valve is open. Verify LPG cylinder is full and valve is open.
If the problem does not exist in LPG mode If the problem does not exist in LPG mode
proceed with the corrective action steps proceed with the corrective action steps
below. below.
If the problem also exists in LPG mode then If the problem
the root cause is most likely to be the root cause is most likely to be
something other than the fuel system something other than the fuel system
See Advanced Diagnostics & Service See Advanced Diagnostics & Service
 
Manual Manual
Test pressure Test pressure regulator
 
See Engine Service Manual See Engine Service Manual
Repair/replace Repair/replace as
See Maintenance section, Primary and See Maintenance section, Primary and
 
Secondary Fuel Filter re Secondary Fuel Filter replacement
Test Test pressure pressure regulator
See Engine Service Manual See Engine Service Manual
 
Test Injector Test Injector operation operation
See Engine Service Manual See Engine Service Manual
 
Check Check for for vacuum vacuum leaks
Between mixer and throttle body Between mixer and throttle body
 
Between throttle body and intake Between throttle body and intake
 
manifold manifold
Between intake manifold and cylinder Between intake manifold and cylinder
 
head head
Action
Manual
also exists in LPG mode then
regulator operation operation
as required required
placement
regulator operation operation
leaks