0340731 JOHNSON EXHAUST HOUSING, Outer

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 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 Crankshaft 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 Rotocoil or 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. Engine Speed Does Not Go Higher Than 1000 to 1200 rpm.32. Rack Solenoid Does Not Stop Engine.33. Engine With "Dashpot" Governor is Slow to Correct Speed or Hunts (Changes Speed Constantly).Engine Crankshaft Will Not Turn When Start Switch Is On Engine Will Not Start Misfiring Or Running Rough Stall At Low Rpm Sudden Changes In Engine Speed (rpm) Not Enough Power Too Much Vibration Loud Combustion Noise (Sound) Valve Train Noise (Clicking) Oil In Cooling System Mechanical Noise (Knock) In Engine Fuel Consumption Too High Loud Valve Train Noise Too Much Valve Lash Valve Rotocoil Or Spring Lock Is Free Oil At The Exhaust Little Or No Valve Clearance Engine Has Early Wear Coolant In Lubrication Oil Too Much Black Or Gray Smoke Too Much White Or Blue Smoke Engine Has Low Oil Pressure Engine Uses Too Much Lubrication Oil Engine Coolant Is Too Hot Starter Motor Does Not Turn Alternator Gives No Charge Alternator Charge Rate Is Low Or Not Regular Alternator Charge Too High Alternator Has Noise Exhaust Temperature Is Too High Engine Speed Does Not Go Higher Than 1000 to 1200 rpm Rack Solenoid Does Not Stop Engine Engine With "Dashpot" Governor Is Slow To Correct Speed Or Hunts (Changes Speed Constantly) Fuel System Identification
FUEL INJECTION PUMP AND GOVERNOR GROUP
FUEL INJECTION PUMP IDENTIFICATION PLATE(1) Location of stamped part number for later FUEL INJECTION PUMP and GOVERNOR GROUP or DRIVE.(2) Location of FUEL INJECTION PUMP GROUP identification plate (earlier engines) on top, right side of injection housing.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 injection nozzle, but it can also be caused by one or more of the reasons that follow: a. Not enough air for good combustion.b. An overload at high altitude.c. Oil leakage into combustion chamber.d. Not enough compression.e. Fuel injection timing retarded.Fuel System Inspection
A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.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 fuel filter. Clean the primary fuel filter, if so equipped.4. To remove air from the fuel system, use one of the procedures that follow for the correct application:PC Engines:
(a) Use the priming pump to remove air from the low pressure side of the fuel system.(b) Loosen (one at a time) the fuel injection line nut one-half turn at the valve cover base adapter. Use the priming pump until fuel without air flows from the loose connections, then tighten the nut. Repeat the procedure for each fuel injection line.DI Engines:
(a) Use the priming pump to remove air from the low pressure side of the fuel system.(b) Loosen one-half turn the fuel injection line nuts at the adapter in the valve cover base. Use the starter motor to turn the engine until fuel without air flows from the loose connections. Tighten the nuts. Because of the check assemblies in the injection pump outlets for the DI engine, the priming pump will not give enough pressure to remove air from the fuel injection lines.5. Inspect the bypass valve in the fuel transfer pump to see that there is no restriction to good operation.