TM10-3930-660-20 Table  2-3. Mechanical Troubleshooting (Cont'd) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION 6. ROUGH IDLE (irregularly firing or engine shaking) Step 1. Check for idle speed too low for the accessories. Adjust idle speed by adjusting accelerator cable as required, para.  5-21. Step 2. Check for high pressure fuel leak. Check for leaks in the high pressure lines, fittings, injection sealing washers, or delivery valve seals. Replace defective parts as required, para. 5-12. Step 3. Check for air in the fuel system. Bleed the fuel system, para. 5-12. Locate and repair the leak. 7. ENGINE RUNS ROUGH OR MISFIRING Step 1. Fuel injection lines leaking. Inspect high pressure lines, fittings, injector sealing washers, or delivery valves for leaks. Replace components as necessary, para.5-12. Step 2. Check for air in the fuel or inadequate fuel supply. Check the flow through the filter and bleed the system, para. 5-12. Locate and correct the air leak. Step 3. Check for contaminated fuel. Verify by operating the engine with clean fuel from a temporary tank. Drain and fill fuel/hydraulic tank if necessary, para. 5-10. 8. ENGINE RPM  WILL  NOT REACH  RATED  SPEED Step 1. Check for overloaded engine. Verify high idle speed without load. Investigate operation to be sure correct gear range is being used, TM10-3930-660-10. Step 2. Check for accelerator linkage wear or incorrect adjustment. Adjust accelerator cable linkage, para. 5-21. 2-30