Usage:
Recommended Procedure
A. MISFIRING AND RUNNING ROUGH
See the chart, Misfiring and Running Rough.
B. PROBLEM WITH VEHICLE or VEHICLE OPERATION
See the chart, Problem With Vehicle or Vehicle Operation.
C. LOW ENGINE RPM
1. Governor Linkage Disconnect the governor linkage at the lever on the governor. Move the governor lever by hand until the linkage inside the governor is against the high idle stop. With the accelerator pedal all the way down, adjust the linkage so that the inside linkage is against the high idle stop. Some trucks are equipped with linkage which has spring force and some are equipped with a governor lever of the break over type. On engines with either of these, adjust the governor linkage .250 in. (6,35 mm) longer than necessary for the inside linkage to be against the high idle stop, this will keep tension on the spring at all times.
NOTE: For trucks with tilt cabs, do not make this check with the cab tilted.
2. Governor High Idle Adjustment If the governor linkage moves the governor lever to the fully open position, check the high idle rpm with a good tachometer. If the high idle rpm is too low, turn the high idle adjustment screw counterclockwise until high idle rpm is correct. See the RACK SETTING INFORMATION for the correct high idle rpm. If high idle rpm can not be made correct with the high idle adjustment screw, there is a problem inside the governor. Disassemble the governor and check for damage to parts or the wrong parts installed in the governor.
D. NOT ENOUGH AIR
3. Inlet Restriction Air inlet restriction will cause low power and too much smoke when under load. Check for a restriction with a water manometer or a vacuum gauge (which measures in inches of water). Connect the gauge to the engine air inlet between the air cleaner and the engine. With gauge installed, run engine at full load rpm and check the restriction. Maximum restriction of the air inlet is 30 inches (762 mm) of water. If the indication is higher than the maximum permissible restriction, remove dirt from the filter element or install a new filter element and check the restriction again. If the indication is still too high, there must be a restriction in the inlet piping.
4. Exhaust Restriction Make a visual inspection of the exhaust system and look for damage to piping or for a bad muffler. If no damage is found, you can also check the system by removing the exhaust pipes from the exhaust manifolds. With the exhaust pipes removed, start and run the engine to see if the problem is corrected.
E. LOW QUALITY FUEL
5. Water in Fuel Remove a small amount of fuel from the tank and check for water in the fuel. If there is water in the fuel, remove fuel from tank until it is free of water. Install a new fuel filter and fill the fuel tank with clean fuel. "Prime" (remove the air and/or low quality fuel from the fuel system) the fuel system as per the OPERATION GUIDE (FEO-45119) until all water is out of the fuel system.
6. Fuel With Low Specific Gravity Remove a small amount of fuel from the tank and measure the API gravity with a fuel hydrometer. The 1P7408 Thermo-Hydrometer can also be used. Special Instruction (GMG00977) gives the test procedure for the 1P7408 Thermo-Hydrometer. Caterpillar engines are rated on fuel having 35 API gravity at 60° F (16° C). If the API gravity of the fuel used is more than 38, the result will be a reduction in power.
F. FUEL SYSTEM PROBLEMS
7. Low Fuel Pressure Remove the cap from the tee at the fuel filter. Connect a pressure gauge to the tee. Run the engine under load and check the pressure. If the pressure is lower than 13 psi (0,9 kg/cm2), install a new fuel filter and clean the primary fuel filter (if so equipped) and check fuel pressure again. If the pressure is still lower than 13 psi (0,9 kg/cm2), connect a vacuum gauge to the inlet side of the fuel transfer pump and run the engine under load. If the inlet vacuum is less than 9 inches (228,6 mm) of mercury, install a new fuel transfer pump. If the inlet vacuum is more than 9 inches (228,6 mm) of mercury, there is a restriction in the fuel supply line and/or the fuel tank.
8. Air in Fuel System With air in the fuel system the engine will normally be difficult to start, run rough and release a large amount of white smoke. Remove the air from the fuel system by either loosening the cap on the tee at the fuel filter, or by loosening the fuel line nuts one at a time at the cylinder heads. Turn the engine with the starter or run the engine until the fuel flow at this connection is free of air. If air is not removed in this way, put 5 psi (0,35 kg/cm2) [CAUTION do not use more than 8 psi (0,56 kg/cm2)] of air pressure to the fuel tank and check for leaks at connections between the fuel tank and the fuel transfer pump. If there are no leaks at the connections, remove the fuel supply line from the tank and connect it to an outside fuel supply. If this corrects the problem the suction line (standpipe) inside the fuel tank has a leak.
9. Rack Setting Too Low Check and make necessary adjustments as per the Testing and Adjusting section of the Service Manual. See the RACK SETTING INFORMATION for the correct rack setting.
10. Rack Will Not Move Freely Remove the cover, used to center the rack, from the fuel injection pump housing. Move the rack in both directions through the full rack travel. The rack must move freely. If the rack does not move freely, check for bent rack, damage to the rack bushings, injection pump plungers not moving free, or the gear segment on the injection pump plungers not correctly engaging the gear teeth on the rack.
11. Fuel Injection Timing Not Correct Check and make necessary adjustments as per Testing and Adjusting section of the Service Manual.
12. Fuel Injection Pump(s) Installed Wrong See the subject (Removing and Installing Fuel Injection pumps) in the Testing and Adjusting section of the Service Manual.
13. Wear or Damage to Fuel Injection Pump(s) If a Caterpillar Fuel Injection Test Bench is available, remove the housing of the fuel injection pump and governor as a unit and test the fuel delivery with the test bench. If a test bench is not available, visually inspect the fuel injection pumps. The plungers must look smooth and shiny. If plungers are not smooth and shiny or if the plungers have scratches or grooves they must not be used again. To remove and install the fuel injection pumps, see the subject (Removing and Installing Fuel Injection Pumps) in the Testing and Adjusting section of the Service Manual.
14. Wrong Fuel Injection Pump Plunger and Barrel Assemblies Installed Plunger and barrel assemblies for the 1140, 1145, and 1150 Engines are different from those for the 1160 Engine. The plungers and barrels for the 1140, 1145, and 1150 Engines have one identification groove. The identification groove on the plungers is between the gear segment and the spring retainer groove, the identification groove on the barrels is under the return spring. The plungers and barrels for the 1160 Engine do not have an identification groove.
Similar pumps, used in a different application, have two identification grooves on the plunger and one identification groove on the barrel. Do not use these pumps in 1100 Series Engines.
Plunger and barrel assemblies are fitted to each other. Do not use a plunger with any other barrel and do not use a barrel with any other plunger.