BUSHING 4565315 - Caterpillar

following events cause unburned gas to remain in the air inlet and in the exhaust manifold:
Emergency stop
Engine overspeed
The Gas Shutoff Valve (GSOV) is commanded to close and the GSOV does not close.
Unsuccessful successive attempts to start the engineUnburned gas may remain in the air inlet and exhaust system after several unsuccessful attempts to start the engine. The unburned gas may increase to a concentration that may ignite during a successive attempt to start the engine.Perform the following procedure in order to purge the unburned gas:
If the Cat Electronic Technician (ET) is not connected to the engine, connect Cat ET to the engine.
Verify that the value of the "Engine Purge Cycle" parameter is equal to 10 seconds less than the value of the "Crank Cycle" parameter.
Set the engine control to the START mode. The engine will crank for the "Engine Purge Cycle Time". Then, the GSOV will be energized and the ignition will be enabled. The engine will start.
Continue with your previous procedure.