VALVE GP-SELECTOR & PRESS CONT 1074409 - Caterpillar

manifold should be as above, minus the delta P across the secondary fuel filter.The pressure drop across the secondary fuel filter is typically at least 35 kPa (5 psi) with a new filter. The pressure differential will increase as the filter accumulates deposits. If fuel pressure in the fuel gallery within the fluid manifold at the injectors decreases to approximately 69 kPa (10 psi), misfiring may occur.A check valve is mounted at the junction of the fuel lines. These fuel lines are located at the rear end of the fuel gallery that is located within the fluid manifold. The valve maintains fuel pressure at low engine speeds. The spring loaded check valve prevents the fuel from draining from the head after engine shutdown.To check the unfiltered fuel pressure, remove the plug from the fuel filter base. Install the connector, the seal and 1U-5470 Engine Pressure Group onto the fuel pressure tap. This will check transfer pump pressure. Operate the engine. To check the pressure within the main gallery, remove the plug from the fuel relief valve. Install the adapter, the seal and 1U-5470 Engine Pressure Group onto the fuel pressure tap. Operate the engine.Note: Make sure that the fuel filter is clean before you check fuel pressure. A restricted fuel filter will cause a lower fuel pressure at the fuel filter tap than the fuel pressure at the fuel relief valve.Finding The Top Center Position For The No. 1 Piston
Table 2
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    Note: The starting position for all timing procedures is with the No. 1 piston at the top center position