Testing & Adjusting (SENR4607-01)
SMCS-
Introduction
NOTE: For Specifications with illustrations, make reference to Specifications for 3208 Industrial & Marine
Engines, SENR4606. If the Specifications in SENR4606 are not the same as in the Systems Operation
and the Testing & Adjusting, look at the printing date on the front cover of each book. Use the
Specifications given in the book with the latest date.
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 given 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.
1. Engine Will Not Start.
2. Misfiring Or Running Rough.
3. Stall At Low rpm.
4. Sudden Changes In Engine rpm.
5. Not Enough Power.
6. Too Much Vibration.
7. Loud Combustion Noise.
8. Loud Noise (Clicking) From Valve Compartment.
9. Oil In Cooling System.
10. Mechanical Noise (Knock) In Engine.
11. Fuel Consumption Too High.
12. Loud Noise From Valves Or Valve Drive Components.
13. Little Movement Of Rocker Arm And Too Much Valve Lash.
14. Valve Spring Lock Is Free.
15. Oil At The Exhaust.
16. Little Or No Valve Lash.
17. Engine Has Early Wear.
18. Coolant In Lubrication Oil.
19. Too Much Black Or Gray Smoke.
20. Too Much VVhite Or Blue Smoke.
21. Engine Has Low Oil Pressure.
22. Engine Uses Too Much Lubrication Oil.
23. Engine Coolant Is Too Hot.
24. Starting Motor Does Not Turn.
25. Alternator Gives No Charge.
26. Alternator Charge Rate Is Low Or Not Regulator.
27. Alternator Charge Is Too High.
28. Alternator Has Noise.
29. Exhaust Temperature Is Too High.
Problem 1. Engine Will Not Start Probable Cause:
1. Empty Fuel Tank Put fuel in fuel tank.
2. Poor 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. Linkage To Sleeve Control Shaft Is Held In Shutoff Position
Check the operation of the shutoff solenoid and the shutoff linkage. Solenoid must pull up to compress
spring for fuel turn on. Check governor linkage for free movement. Sleeves must turn freely on fuel injection
pump plungers in all positions of sleeve control shaft. The thrust collar must turn freely on the governor
shaft at all positions between shutoff and full load. If linkage does not move freely under these conditions,
clean all parts thoroughly. Inspect all parts for wear and make replacement where needed.
6. Fuel Pressure Is Too Low
Replace the fuel filter. Inspect the bypass valve for free movement. Install a new bypass valve if necessary.
7. 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 & Adjusting.
8. Fuel System Not Timed Correctly To Engine Make adjustment to timing if necessary.
9. Constant Purge Valve Stays Open (not enough fuel pressure for starting)
Replace constant purge valve.
10. No Overfuel Spring Install an overfuel spring.
11. Fuel Ratio Control Has ADefect
Check fuel ratio control setting. Adjust if necessary. Check operation of solenoid.
Problem 2. 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 severe bends in the fuel line betvveen 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 205 ± 35 kPa (30 ± 5 psi). If fuel pressure is lovver than above
pressure, install a nevv fuel filter element. Inspect the fuel bypass valve for free movement. Install a nevv
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. Make reference to
Removing Air From Fuel System in Testing & Adjusting.
3. Leak Or Break In Fuel Injection Line Betvveen Fuel Injection Pump And Fuel Injection Nozzle Install a
nevv fuel injection line.
4. VVrong Valve Lash
Make adjustment according to Testing & 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 fuel
injection line for each cylinder, one at a time. Find the cylinder vvhere 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.
Problem 3. 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 severe bends in the fuel line betvveen
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 205 ± 35 kPa (30 ± 5 psi). If fuel pressure is lovver than
above pressure, install a nevv fuel filter element. Inspect the bypass valve for free movement. Install a
nevv bypass valve if necessary.
2. Idle rpm Too Lovv
Make adjustment to governor so idle rpm is the same as given in the TMI (Technical Marketing
Information) orthe Fuel Setting And Related Information Fiche.
3. Defect In Fuel Injection Nozzle
Install a nevv fuel injection nozzle.
4. VVrong Valve Lash
Make adjustment according to Testing & Adjusting.
5. Spring For Dashpot Governor Installed VVrong
Install spring correctly.
Problem 4. Sudden Changes In Engine RPM
Probable Cause:
1. 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 & Adjusting.
2. Broken Torsion Spring On Sleeve Control Shaft
Install nevv parts as needed.
3. Linkage In Governor Does Not Move Freely
Clean all linkage and inside of governor housing. Install nevv parts for those parts that have
damage.
4. Governor Springs Not Completely On Spring Seat Put
springs completely on spring seat.
5. Spring For Dashpot Governor Installed VVrong
Install spring correctly
Problem 5. Not Enough Power
Probable Cause:
1. Poor 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.
2. Fuel Pressure Is Low
Make sure there is fuel in the fuel tank. Look for leaks or severe 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 205 ± 35 kPa (30 ± 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.
3. 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 & Adjusting.
4. Leaks In Air Inlet System
Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.
5. VVrong Fuel Setting
Make adjustments as necessary.
6. Governor Linkage
Make adjustment to get full travel of linkage. Install new parts for those that have damage or defects.
7. Defect In Timing Advance Unit Replacement of timing advance unit is needed.
8. VVrong Valve Lash
Make adjustment according to Testing & Adjusting.
9. Defect In Fuel Injection Nozzle
Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the fuel
injection line for each cylinder, one at a time. Tighten each fuel line nut before loosening the next one. 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.
10. VVrong Fuel Injection Timing Make adjusting to timing.
11. Fuel Shutoff Solenoid or Shutoff Linkage Causing A Restriction In The Travel Of The Shaft For The
Sleeves
Check for correct full power with solenoid removed. If the engine has full power with the solenoid removed,
the problem is in the solenoid or the shutoff linkage. Check for free travel of the linkage.
12. Constant Purge Stays Closed Replace constant purge valve.
