850904 Volvo.Penta Screw

Troubleshooting
Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.This list of problems, causes, and corrections, will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.Troubleshooting Index
1. Engine Will Not Turn When Start Switch Is On.2. Engine Will Not Start.3. Misfiring or Running Rough.4. Stall at Low rpm.5. Sudden Changes In Engine rpm.6. Not Enough Power.7. Too Much Vibration.8. Loud Combustion Noise.9. Valve Train Noise (Clicking).10. Oil In Cooling System.11. Mechanical Noise (Knock) In Engine.12. Fuel Consumption Too High.13. Loud Valve Train Noise.14. Too Much Valve Lash.15. Valve Spring Lock is Free.16. Oil at the Exhaust.17. Little or No Valve Clearance.18. Engine Has Early Wear.19. Coolant in Lubrication Oil.20. Too Much Black Or Gray Smoke.21. Too Much White or Blue Smoke.22. Engine Has Low Oil Pressure.23. Engine Uses Too Much Lubrication Oil.24. Engine Coolant Is Too Hot.25. Starter Motor Does Not Turn.26. Alternator Gives No Charge.27. Alternator Charge Rate Is Low or Not Regular.28. Alternator Charge Too High.29. Alternator Has Noise.30. Exhaust Temperature Too High.31. Fan Speed Too Low or Too High. 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. Finding the source of the problem is difficult, especially when there is smoke from the exhaust. Smoke from the exhaust can be caused by a bad fuel injection valve, but it can also be caused by one of the problems that follow: a. Not enough air for good combustion.b. An overload at high altitude.c. Burning of too much oil.d. Not enough compression.Fuel System Inspection
1. Look at the reading on the gauge for fuel pressure. Not enough fuel pressure is an indication of a problem with the components that send fuel to the engine.2. 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.3. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend.4. Install a new fuel filter. Clean the primary fuel filter.5. Remove any air that may be in the fuel system. If there is air in the fuel system, use the priming pump and loosen the nuts that hold the fuel lines to the outside of the cylinder head, one at a time. Do this until fuel, with no air, comes from the fuel line connection.6. Inspect the fuel bypass valve to see that there is no restriction to good operation.Testing Fuel Injection Equipment
Before installation of a fuel injection valve, inspect the valve and precombustion chamber for dirt or damage on the surfaces that go together. Tighten the fuel injection valve on the body finger tight. Tighten the fuel injection valve retaining nut to a first torque of 85 lb.ft. (115 N m) and then tighten to 105 5 lb. ft. (142 7 N m). Too much torque can cause damage inside the valve. Too little torque can let the valve become larger or crack and a fuel leak will be the result. To check for a fuel injection valve that leaks, remove the plugs from the side of the camshaft housing and look for fuel to come out while the engine is running.An easy check can be made to find the cylinder that is misfiring, or running rough, and causing black smoke to come out of the exhaust pipe.Run the engine at the speed that gives misfiring. Loosen the fuel line nut at a fuel injection pump or valve. This will stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine running. Be sure to tighten each fuel line nut after the test before the next fuel line nut is loosened. Check each cylinder by this method. When a cylinder is found where the loosened fuel line nut does not make a difference in engine running, test the injection pump and injection valve for that cylinder.Checking The Fuel Injection Valves
Check the fuel injection valves for:1. Too much carbon on the tip of the nozzle or in the nozzle orifice.2. Wear of the orifice.3. Dirt in nozzle screen.A capsule-type fuel injection valve can be tested on the 5P4150 Nozzle Tester. Special Instruction Form No. SEHS7292 gives instructions for the test procedure.Removing and Installing Fuel Injection Pump Assemblies
TIMING PIN ASSEMBLY1. Remove the timing pin from its storage position and install one of the bolts (head down) through one of the flange holes. Install a nut at the top to hold the bolt in place. The bolt head is a stop for the timing pin.2. Put timing pin (1) in the timing hole. Move the governor control or rack linkage until the timing pin goes through the notch in the rack. The pin is in place when the head of the bolt contacts the fuel pump housing. With the rack in this position, the centerline of the second tooth on each fuel pump gear will be in alignment with the correct tooth on the rack. This is the position at which the fuel injection pump assemblies can be removed and installed.
TIMING PIN ZEROES THE RACK
1. Timing pin.3. Disconnect the fuel injection line from the fuel injection pump assembly. Remove the bolts that hold the fuel injection pump assembly