Lull 944E-42 Service Manual - Manual (Page 252)

Engine: Cummins 4BT 3.9, B4.5T and QSB 4.5T
7.50 Model 644E-42/944E-42 Rev. 6/04
7.12 TROUBLESHOOTING
Trouble Possible Causes (see key, below)
Low Cranking Power
Will Not Start
Difficult Starting
Lack of Power
Misfiring
Excessive Fuel Consumption
Black Exhaust
Blue/White Exhaust
Low Oil Pressure
Knocking
Erratic Running
Vibration
High Oil Pressure
Overheating
Excessive Crankcase
Pressure
Poor Compression
Starts and Stops
1, 2, 3, 4
5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 31, 32, 33
5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 24, 29, 31, 32, 33, 61,
63
8, 9, 10, 11, 12, 13, 14, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31, 32, 33, 61, 63
8, 9, 10, 12, 13, 14, 16, 18, 19, 20, 25, 26, 28, 29, 30, 32
11, 13, 14, 16, 18, 19, 20, 22, 23, 24, 25, 27, 28, 29, 31, 32, 33, 63
11, 13, 14, 16, 18, 19, 20, 22, 24, 25, 27, 28, 29, 31, 32, 33, 61, 63
4, 16, 18, 19, 20, 25, 27, 31, 33, 34, 35, 45, 56, 62
4, 36, 37, 38, 39, 40, 42, 43, 44, 58
9, 14, 16, 18, 19, 22, 26, 28, 29, 31, 33, 35, 36, 45, 46, 59
7, 8, 9, 10, 11, 12, 13, 14, 16, 20, 21, 23, 26, 28, 29, 30, 33, 35, 45, 59
13, 14, 20, 23, 25, 26, 29, 30, 33, 45, 47, 48, 49
4, 38, 41
11, 13, 14, 16, 18, 19, 24, 25, 45, 50, 51, 52, 53, 54, 57
25, 31, 33, 34, 45, 55, 60
11, 19, 25, 28, 29, 31, 32, 33, 34, 46, 59
10, 11, 12
Key to Possible Causes
1. Battery charge low
2. Malfunctioning electrical
connection
3. Faulty starter motor
4. Incorrect grade of lubricating
oil
5. Low cranking speed
6. Fuel tank empty
7. Faulty stop control operation
8. Fuel inlet restricted
9. Faulty fuel lift pump
10. Clogged fuel filter
11. Restricted air cleaner
12. Air in fuel system
13. Faulty fuel injection pump
14. Faulty fuel injectors or
incorrect type
15. Incorrect use of cold start
equipment
16. Faulty cold start equipment
17. Broken fuel injection pump
drive
18. Incorrect fuel pump timing
19. Incorrect valve timing
20. Poor compression
21. Blocked fuel tank vent
22. Incorrect grade of fuel
23. Sticking throttle or restricted
movement
24. Exhaust pipe restriction
25. Leaking cylinder head gasket
26. Overheating
27. Cold running
28. Incorrect tappet adjustment
29. Sticking valves
30. Incorrect high pressure pipes
31. Worn cylinder bores
32. Pitted valves and seats
33. Broken, worn or sticking piston
ring(s)
34. Worn valve stems and guides
35. Restricted air cleaner
36. Worn or damaged bearings
37. Insufficient oil in sump
38. Inaccurate gauge
39. Oil pump worn
40. Pressure relief valve sticking
open
41. Pressure relief valve sticking
closed
42. Broken relief valve spring
43. Faulty suction pipe
44. Restricted oil filter
45. Piston seizure/pick up
46. Incorrect piston height
47. Damaged fan
48. Faulty engine mounting
49. Incorrectly aligned flywheel
housing or incorrectly aligned
flywheel
50. Faulty thermostat
51. Restriction in water jacket
52. Loose fan belt
53. Restricted radiator
54. Faulty water pump
55. Restricted breather pipe
56. Damaged valve stem oil
deflectors (If fitted)
57. Coolant level too low
58. Blocked sump strainer
59. Broken valve spring
60. Exhauster or vacuum pipe leak
61. Turbo impeller damaged or dirty
62. Turbo lubricating oil seal leak
63. Induction system leaks