947941 Volvo.Penta Hexagon nut

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 On2. Engine Will Not Start3. Misfiring Or Running Rough4. Stall At Low rpm5. Sudden Changes In Engine rpm6. Not Enough Power7. Too Much Vibration8. Loud Combustion Noise9. Loud Noise (Clicking) From Valve Compartment10. Oil In Cooling System11. Mechanical Noise (Knock) In Engine12. Fuel Consumption Too High13. Loud Noise From Valves Or Valve Drive Components14. Little Movement Of Rocker Arm And Too Much Valve Clearance15. Valve Rotocoil or Spring Lock Is Free16. Oil At The Exhaust17. Little Or No Valve Clearance18. Engine Has Early Wear19. Coolant In Lubrication Oil20. Too Much Black Or Gray Smoke21. Too Much White Or Blue Smoke22. Engine Has Low Oil Pressure23. Engine Uses Too Much Lubrication Oil24. Engine Coolant Is Too Hot25. Starter Motor Does Not Turn26. Alternator Does Not Charge27. Alternator Charge Rate Is Low Or Not Regular28. Alternator Charge Is Too High29. Alternator Has Noise30. Exhaust Temperature Is Too HighProblem 1. Engine Will Not Turn When Start Switch Is On
Probable Cause:1. Battery Has Low Output Check condition of battery. Charge battery or make replacement as necessary.2. Wiring Or Switches Have Defect Make repairs or replacement as necessary.3. Starter Motor Solenoid Has A Defect Install a new solenoid.4. Starter Motor Has A Defect Make repair or replacement of starter motor.5. Inside Problem Prevents Engine Crankshaft From Turning If the crankshaft can not be turned after disconnecting the driven equipment, remove the fuel nozzles and check for fluid in the cylinders while turning the crankshaft. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, piston seizure, or wrong pistons installed in the engine.Problem 2. Engine Will Not Start
Probable Cause:1. Empty Fuel Tank Put fuel in fuel tank.2. Low Quality Fuel Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.3. Dirty Fuel Filter Install new fuel filter.4. Dirty Or Broken Fuel Lines Clean or install new fuel lines as necessary.5. Fuel Pressure Is Too Low Replace the fuel filter. Inspect the bypass valve for free movement. Install a new bypass valve if necessary.6. Air In The Fuel System Find the air leak in the fuel system and correct it. Remove air from the fuel system. Make reference to Removing Air From Fuel System in Testing and Adjusting.7. Fuel System Not Timed Correctly To Engine Make adjustment to timing if necessary.8. Constant Bleed Valve Stays Open (not enough fuel pressure for starting) Replace constant bleed valve.9. No Over Fueling Spring Install an over fueling spring.10. Fuel Ratio Control Has A Defect Check fuel ratio control setting. Adjust if necessary. Check operation of solenoid.11. Slow Cranking Speed Check condition of battery and replace if necessary.12. No Fuel In The Housing For The Fuel Injection Pumps Fill the housing for the fuel injection pumps with fuel with the priming pump.13. Fuel Has "Cloud Point" Higher Than Atmospheric Temperature ("Cloud Point" = Temperature Which Makes Wax Form In Fuel). Drain the fuel tank lines, and fuel injection pump housing. Change the fuel filter. Fill the tank with fuel which has the correct "cloud point".Problem 3. Misfiring Or Running Rough
Probable Cause:1. Fuel Pressure Is Low Make sure there is enough fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 240 35 kPa (35 5 psi). If fuel pressure is lower than above pressure, install a new fuel filter element. Inspect the fuel bypass valve for free movement. Install a new fuel bypass valve if necessary.2. Air In The Fuel System Find the air leak in the fuel system and correct it. Remove air from the fuel system. See Fuel System in Testing and Adjusting.3. Leak Or Break In Fuel Line Between Injection Pump And Injection Valve Install a new fuel line.4. Wrong Valve Lash Make adjustment according to Testing and Adjusting.5. Defect In Fuel Injection Nozzle Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the injection line for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the fuel injection nozzle for that cylinder. Install new parts where needed.6. Wrong Fuel Injection Timing Make adjustment to timing.7. Bent Or Broken Push Rod Replacement of push rod is necessary.8. Worn Valve Seat Or Face Of Valve Reconditioning of cylinder head is needed.Problem 4. Stall At Low RPM
Probable Cause:1. Fuel Pressure Is Low Make sure there is enough fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 240 35 kPa (35 5 psi). If fuel pressure is lower than above pressure, install a new fuel filter element. Inspect the bypass valve for free movement. Install a new bypass valve if necessary.2. Idle RPM Too Low Make