Series 50G/60G Troubleshooting – Section 8.6 Shutdown

Section 8.6
Shutdown

Backfire at engine shutdown is often caused by excess natural gas in the fuel lines. ‪

1. Measure the fuel line between the low pressure shutoff valve and the low pressure regulator.
   1. If the fuel line is longer than 46 cm (18 in.), replace the fuel line with a shorter line. If the engine now operates normally, troubleshooting is done.
   2. If the fuel line is not longer than 46 cm (18 in.), go to step 2 .
2. Listen to the low pressure shutoff valve for additional fuel flow after the engine has been turned off.

   Note: The low pressure shutoff valve may not be completely closing upon engine shutdown. This condition allows the small amount of fuel left in the fuel line to continuously flow to the engine and may cause a backfire.

   1. If the valve continues to flow fuel to the engine after shutdown, replace the fuel shutoff valve. Refer to "8.3.3 Replacing the Throttle for Models 6067–TKG8 and 6047–TKG8" .
   2. If the valve is in proper working order and a "backfire" condition is still occurring, contact the Detroit Diesel Technical Service.