5337400NP Mercruiser STERNDRIVE UNIT, Complete

Troubleshooting
Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, make reference to the cause and correction on the pages that follow.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 is only a guide and cannot give all possible problems and corrections. The service personnel must find the problem and its source, then make the necessary repairs.1. Engine Crankshaft Will Not Turn When Start Switch Is On.2. Engine Will Not Start.3. Engine Misfires Or Rungs 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 Rotocoil Or Spring Lock Is Free.16. Oil At The Exhaust.17. Little Or No Valve Lash.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. Exhaust Temperature Is Too High.26. Starting Motor Does Not Turn.27. Alternator Gives No Charge. Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On Probable Cause:1. Battery Has Low Output Make Reference to Problem 26.2. Wires or Switches Have Defect Make Reference to Problem 26.3. Starting Motor Solenoid Has A Defect Make Reference to Problem 26.4. Starting Motor Has a Defect Make Reference to Problem 26.5. Inside Problem Prevents Engine Crankshaft From Turning If the crankshaft can not be turned after the driven equipment is disconnected, remove the fuel injection nozzles and check for fluid in the cylinders when the crankshaft is turned. 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. Starting Motor Turns Too Slow Make Reference to Problem 27.2. Dirty Fuel Filter Install new fuel filter.3. Dirty or Broken Fuel Lines Clean or install new fuel lines as necessary.4. Fuel Transfer Pump At starting rpm, the minimum fuel pressure for fuel transfer pump must be 20 kPa (3 psi). If fuel pressure is less than 20 kPa (3 psi), change the fuel filter element. Look for air in the fuel system. If fuel pressure is still low, install a new fuel transfer pump.5. No Fuel To Cylinders Put fuel in fuel tank. "Prime" (remove the air and/or low quality fuel) the fuel system.6. 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. See Diesel Fuels and Your Engine, SEBD0717.7. Wrong Fuel Injection Timing Make adjustment to timing.8. Shutoff Solenoid Will Not Move to Extended Position The solenoid must get electricity to stop the engine. Operate the control for the shutoff solenoid and see if the solenoid makes a noise (clicking sound). If this sound can be heard and the engine will not start, remove the solenoid. Now see if the engine will start. If the engine starts, the shutoff solenoid either needs an adjustment or it is defective and replacement of the solenoid is necessary. Problem 3: Engine Misfires Or Runs Rough Probable Cause:1. Fuel Pressure is Low Make sure there is 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.If fuel pressure is lower than 170 kPa (25 psi) install a new filter element. The outlet pressure of the fuel transfer pump at full load must be 240 kPa (35 psi). If fuel pressure is still low, install a new fuel transfer pump.2. Air in Fuel System Find the air leak in the fuel system and correct it. If air is in the fuel system, it will probably get in on the suction side of fuel transfer pump.3. Leak or Break in Fuel Line Between Injection Pump and Fuel Injection Nozzle Install a new fuel line.4. Wrong Valve Lash. Make adjustment according to the Subject, Valve Lash Setting.5. Defect in Fuel Injection Nozzle(s) or Injection Pump(s) Run engine at rpm that misfires the most and runs the roughest. Then loosen a fuel line nut on the fuel injection nozzle for each cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the fuel injection pump and 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. 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" and remove the air from the system with the priming pump. Problem 4: Stall At Low RPM Probable Cause:1. Fuel Pressure is Low Make sure there is 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.If fuel pressure is lower than 170 kPa (25 psi) install a new fuel filter element. The outlet pressure of the fuel transfer pump at full load must be 240 kPa (35 psi). If fuel pressure is still low, install a new fuel transfer