905654 Volvo.Penta Drive screw

Fuel System
Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system.Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a bad fuel injector, but it can also be caused by one or more of the reasons that follow:* Not enough air for good combustion.* An overload at high altitude.* Oil leakage into combustion chamber.* Not enough compression.Fuel System Inspection
A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.Fuel System
Fuel System
(1) Tube assembly (return to tank from fuel passage in cylinder head). (2) Fuel outlet port (to tank). (3) Tube assembly (from transfer pump to fuel filter base). (4) Tube assembly (from fuel filter base to fuel passage in cylinder head). (5) Fuel inlet port (to fuel transfer pump). (6) Screen. (7) Fuel filter.1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend.3. Install a new secondary fuel filter. Clean screen (6) located in the inlet fitting of the fuel transfer pump.4. Inspect the orifice in tube assembly (1) to see that there is no restriction for proper operation.Checking Engine Cylinders Separately
Temperature of an exhaust manifold port, when the engine runs at low idle speed, can be an indication of the condition of a fuel injector. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication of an inoperative injector. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder, caused by a malfunctioning injector. The difference between cylinders should be no more than 70°C (158°F).With the valve cover removed and the engine idling, the control shaft levers allow each injector to be actuated individually to the "FUEL ON" position for a few seconds. This causes excess fuel to be injected into that particular cylinder, causing a loud combustion "knock". If actuating an injector in this fashion briefly does not result in a loud combustion "knock", there may be a problem with the injector, the fuel supply to the injector, or the seal between the injector and the brass sleeve.Use the 1U8865 Infrared Thermometer to check exhaust temperature. The Operator's Manual, Form No. NEHS0510, for the 1U8865 Infrared Thermometer gives complete operating and maintenance instructions for this tool.Start Up Procedure
Use this procedure when an engine is started for the first time after work is done on the fuel system or governor.1. Disconnect the air inlet system from the turbocharger.2. Have a person in position near the turbocharger air inlet with a piece of steel plate large enough to completely cover the turbocharger air inlet.
Be careful when plate is put against air inlet opening. Due to excessive suction, the plate can be pulled quickly against air inlet opening. To avoid crushed fingers, do not put fingers between plate and air inlet opening.
3. Start the engine. If the engine starts to run too fast or runs out of control, immediately put the steel plate against the turbocharger air inlet. This will stop the air supply to the engine, and the engine will stop.Governor
The only "ON-ENGINE" adjustment to the governor is the low idle setting. All other governor adjustments (including the high idle/throttle stop setting) are to be done "OFF-ENGINE" on the governor calibration bench. Refer to Special Instruction, Form No. SEHS8868 for procedures and tooling required to bench test the governor. If governor disassembly and assembly is required, see Form No. SENR6454. The fuel setting (rack setting), fuel timing and injector synchronization adjustments are performed "ON-ENGINE" and are located under the valve cover. See the topics Fuel Setting, Fuel Timing and Injector Synchronization.
Low Idle Adjustment
(1) Low idle screw.The low idle screw (1) is normally set during the bench test procedure. However, if the low idle setting is not satisfactory, use 1U6672 Wrench to loosen the locknut and adjust low idle screw (1) to the desired low idle speed. Tighten the locknut and recheck the low idle setting. Refer to the Fuel Setting And Related Information Fiche for the correct low idle speed.Fuel Pressure
5P2720 Self-Sealing Probe Adapter and 5P2718 Pressure Probe may be used with the tools needed, to allow installation of pressure probes in the future.
1U5470 Engine Pressure GroupThe 1U5470 Engine Pressure Group can be used to check engine fuel pressures.This tool group has a gauge to read fuel pressure to the cylinder head. Special Instruction, Form No. SEHS8907 is with the tool group and gives information for its use.
Fuel Return Line
(1) Cylinder head. (2) Pressure regulating orifice. (3) Tube assembly (return to tank from cylinder head fuel gallery). (4) Check valve assembly. (5) Fuel outlet port (to tank). (6) Fuel gallery.The fuel pressure to the cylinder head fuel gallery (6) should be 200 to 400 kPa (29 to 58 psi) at rated rpm and load condition. At low idle, the pressure regulating orifice (2) in tube assembly (3) maintains a minimum fuel pressure of 50 kPa (7.2 psi) to the injectors. Check valve (4) prevents fuel from leaving the cylinder head fuel gallery during shutdown.
Fuel Pressure Test
(7) Fuel pressure tap (unfiltered). (8) Fuel filter base. (9) Pressure tap (filtered fuel).To check the unfiltered fuel pressure, remove the plug from fuel pressure tap (7). Install the adapter, seal and 1U5470 Engine Pressure Group to fuel pressure tap (7). Operate the engine. To check the filtered fuel pressure, remove the plug from fuel pressure tap (9). Install the adapter, seal and 1U5470 Engine Pressure Group to fuel pressure tap (9). Operate the