21. IDLES ROUGH WITHOUT ABNORMAL NOISE OR SMOKE, WILL NOT CLEAR UP

TM 9-2320-289-34 Table 2-1. Mechanical Troubleshooting (Con’t) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION WARNING Use extreme caution to ensure that clothing or tools DO NOT get caught in truck’s operating drivebelts. Failure to follow this warning may result in serious injury to personnel or equipment damage. Step 3. Start engine, Depress bottom of rocker lever on right side of fuel injector pump. If engine sound doesn’t change, remove and inspect fuel injector pump servo advance piston assembly. (See paragraph 3-40) Step 4. Start engine. Loosen fuel injector line fitting at any fuel injector nozzle until fuel starts to come from fitting. If there is no engine rpm drop, test fuel injector nozzle. (See paragraph 3-36) If there is engine rpm drop, tighten fitting to 20 Ib. -ft. (27 N.m) with crowfoot attachment J-29698-A and repeat check for each fuel injector nozzle. 21. IDLES ROUGH WITHOUT ABNORMAL NOISE OR SMOKE, WILL NOT CLEAR UP Step 1. Check fuel injector pump timing. (See paragraph 3-44) Step 2. Test each fuel injector nozzle. (See paragraph 3-36) Step 3. Remove governor cover. (See paragraph 3-38) Check for black particles. If black particles are evident, replace governor weight retaining ring. (See paragraph 3-42) Step 4. Test fuel injector pump, (See paragraph 3-44) Step 5. Test compression of each cylinder. (See paragraph 3-2) 22. STARTS BUT WILL NOT CONTINUE TO RUN AT IDLE Step 1. Check fuel injector pump timing. (See paragraph 3-44) Step 2. Have assistant start engine. Check fast idle solenoid to see if solenoid holds fuel injector pump lever in fast idle position. If fast idle solenoid does not operate properly, perform Electrical Troubleshooting malfunction #7. Step 3. Test each fuel injector nozzle. (See paragraph 3-36) Step 4. Test fuel injector pump, (See paragraph 3-44) Step 5. Test compression of each cylinder. (See paragraph 3-2) 2-18