Doosan D20S-5 Operation & Maintenance Manual page 131

NO START
Checks
DEFINITION: The engine cranks OK but does not start.
Preliminary Checks
ECM Checks
Sensor Checks
Fuel System
Checks
Ignition System
Checks
None
Use the DST to :
• Check for proper communication with both the ECM
• Check all system fuses engine fuse holder. Refer to Engine Controls Schematics.
• Check battery power, ignition power and ground circuits to the ECM. Refer to
Engine Control Schematics. Verify voltage and/or continuity foreach.
• Check the TMAP sensor.
• Check the cam angle sensor for output (RPM).
Important: A closed LPG manual fuel shut off valve will create a no start condition.
• Check for air intake system leakage between the mixer and the throttle body.
Verify proper operation of the low pressure lock-off solenoids.
• Verify proper operation of the fuel control solenoids.
• Check the fuel system pressures.
• Refer to the LPG Fuel System Diagnosis.
• Check for proper mixer air valve operation.
Note: LPG being a gaseous fuel requires higher secondary ignition system voltages
for the equivalent gasoline operating conditions.
1. Check for the proper ignition voltage output with J 26792 or the equivalent.
2. Verify that the spark plugs are correct for use with LPG.
Check the spark plugs for the following conditions:
• Wet plugs.
• Cracks.
• Wear.
• Improper gap.
• Burned electrodes.
• Heavy deposits.
• Check for bare or shorted ignition wires.
• Check for loose ignition coil connections at the coil.
Action
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Operation Section