PIN AS 1118443 - Caterpillar

Probable Causes
Air in fuel
Poor fuel quality
Incorrect low idle setting
Incorrect fuel setting
Incorrect fuel injection timing
Faulty fuel injector nozzle
Problem with the governor
Faulty fuel injection pumpRecommended Repairs
Air in the Fuel
Check for air in the fuel system. Refer to Troubleshooting, "Air in Fuel".Poor Fuel Quality
Ensure that there is good, clean fuel in the tank. When possible, interview the operator in order to determine if fuel quality is in question. Try to determine if the engine started misfiring soon after refueling. Refer to Troubleshooting, "Fuel Quality".Incorrect Low Idle Setting
Verify that the low idle speed setting is correct. Refer to Systems Operation, Testing and Adjusting, "3406C Diesel Truck Engine".Incorrect Fuel Setting
The fuel setting procedure can be performed with the governor and fuel injection pump on the engine. Refer to System Operation, Testing and Adjusting, "3406C Diesel Truck Engine" for the correct procedure.Incorrect Fuel Injection Timing
Check fuel injection timing. Refer to Systems Operation, Testing And Adjusting, "3406C Diesel Truck Engine" for details.Faulty Fuel Injector Nozzles
The fuel injection nozzles are not serviced. Remove the injectors from the engine and refer to System Operation, Testing and Adjusting, "3406C Diesel Truck Engine" for the proper testing procedure. Replace the fuel injector nozzles, as needed.Problem With the Governor
Ensure that the governor is operating properly. Refer to Troubleshooting, "Governor Instability".Faulty Fuel Injection Pump
Test the fuel injection pump. Refer to the Tool Operating Manual, "Install and Test Fuel Injection Pumps Used on 3406B, 3406C, and 3406 PEEC Engines Using the 4C8192 Heavy-Duty Coupling on Fiets" for the test procedure.