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Flame Start System in Cummins C8.3 Engines

diesel engine flame intake heater

Customer Terry M. contacted us regarding the omission of information on the flame start system (intake heater) in the Cummins C8.3 engine service manual. While most C series engines are equipped with a grid/wafer style electric heater, some are equipped with an open flame type heater, which uses diesel fuel and a spark plug to preheat the intake before starting. Terry was able to locate a service bulletin in Cummins archives which is attached below (PDF). This bulletin provides general information, inspection, removal and installation procedures.

The flame start system is available on the C Series automotive engines only with either a 12-VDC or 24-VDC electrical system.
The flame start system burns a small amount of diesel fuel in the intake manifold to aid starting in cold ambient temperature conditions. The system also operates in a post-start mode to reduce white smoke.
The intake cold-start control module monitors engine temperature. When the engine temperature is greater than 7°C (45°F], the flame start system will not be activated. Below 7°C (45°F], the system will operate as follows:

Preheat Cycle
When the engine temperature is below 7°C [45°F], turn the ignition key to the RUN position. When the key is in this position, the WAIT-TO-START lamp will illuminate for approximately 25 seconds. The engine should not be cranked until the WAIT-TO-START lamp shuts off. If the engine is cranked before the preheat cycle is complete, the process is aborted. The controller is reset each time the ignition is turned off.

Engine-Starting Cycle
When the WAIT-TO-START lamp goes out, the preheat cycle is complete. Depress the accelerator pedal all the way to the floor and crank the engine. The engine must be cranked within 30 seconds. If the engine is not cranked within 30 seconds, the preheat cycle needs to be repeated (step 1 ).

Post-heat Cycle
Post-heating occurs as the flame plugs continue to burn while the engine is running. Post-heating helps warm the engine faster and eliminates white smoke. Post-heating times are determined by the engine temperature upon start-up.

Cummins Inc.

Cummins C8.3 Series Engine Troubleshooting & Repair Manual

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