D330, D333, 3304, 3306 – Fuel Ratio Control

Fuel ratio control bolt (7) is connected by a slot in collar (3) and bolt (4) through the engine governor to the fuel injection pump rack. An air line from the engine inlet manifold supplies manifold pressure air to the chamber inside cover (5).

When the engine is accelerated, or the load on the engine increases, bolt (7) in collar (3) restricts the movement of the fuel rack until the turbocharged boost of air in the inlet manifold and inside the fuel ratio control cover (5) forces diaphragm (2) to compress spring (6). Compressing spring (6) moves bolt (7) which relieves the restriction from collar (3) and the fuel rack. This allows the fuel rack to increase the fuel as the turbocharged air pressure increases with the increase in engine rpm. The compressed force of spring (1) can be adjusted if it is necessary to correct the fuel-to-air ratio.

1. Spring. 2. Diaphragm. 3. Collar. 4. Bolt. 5. Cover. 6. Spring. 7. Bolt.

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