TUBE A. 8S7621 - Caterpillar

Introduction
For Specifications with illustrations, make reference to ENGINE SPECIFICATIONS FOR D342 INDUSTRIAL & MARINE ENGINES, Form No. REG01362. If the Specifications in Form No. REG01362 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back 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 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.1. Engine 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. Loud Noise (Clicking) From Valve Compartment.10. Oil In Cooling System.11. Mechanical Noise (Knock) In Engine.12. Fuel Consumption Too High.13. Loud Noise From Valves or Valve Drive Components.14. Little Movement of Rocker Arm and Too Much Valve Clearance.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. Starting 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. 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. Finding the source of the problem is difficult, especially when smoke is coming from the exhaust. Smoke coming from the exhaust can be caused by a bad fuel injection valve, but it can also be caused by the following: a. Not enough air for good combustion.b. An overload at high altitude.c. Burning of too much oil.d. Not enough compression.Fuel System Inspection
1. Look at the reading on the gauge for fuel pressure. Not enough fuel pressure is an indication of a problem with the components that send fuel to the engine.2. 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.3. Check the fuel lines for fuel leakage. Be sure the