Doosan D20S-5 Operation & Maintenance Manual page 97

Problem
Engine Stalls
Rough Idle
Probable Cause
Fuel Lock-off malfunction
Faulty vapor connection between
the pressure regulator/converter
and the mixer
Pressure regulator freezes
Pressure regulator malfunction
Vacuum leak
Air/Fuel Mixer malfunction
Engine Mechanical
Faulty vapor connection between
the pressure regulator/converter
and the mixer
Pressure regulator malfunction
Vacuum leak
Air/Fuel Mixer malfunction
Corrective Action
Repair/replace Fuel Lock-off
See Engine Service Manual
Check connection
Verify no holes in hose
Clamps must be tight
Look
collapsed hose
Check level in cooling system
Must be full, check coolant strength
-35F minimum
Check coolant hoses
Watch for kinks and/or pinched hoses
Verify one pressure hose and one
return hose
Test pressure regulator operation
See Engine Service Manual
Check for vacuum leaks
Between mixer and throttle body
Between throttle body and intake
manifold
Between intake manifold and cylinder
head
Check mixer
See Engine Service Manual
See Engine Manufacturers Service Manual
Check connection
Verify no holes in hose
Clamps must be tight
Look
collapsed hose
Test pressure regulator operation
See Engine Service Manual
Check for vacuum leaks
Between mixer and throttle body
Between throttle body and intake
manifold
Between intake manifold and cylinder
head
Check mixer
See Engine Service Manual
-95-
Operation Section
for kinked, pinched
for kinked, pinched
and/or
and/or