TM 10-3930-671-24 Table 2-2. Unit Troubleshooting Procedures - CONT. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION ENGINE (CONT.) 2. ENGINE DOES NOT RUN EVENLY. Step 1. Check if fuel lines and fittings are loose. If fuel lines and/or fittings are loose, tighten or replace; then, bleed fuel system (Appendix F, Fuel System, Section 5.0), and prime fuel system (Appendix F, Diesel Fuel Injection System, Section 5.3). If fuel lines and fittings are secure, go to step 2. Step 2. Test fuel supply pressure at engine idle (650-700 rpm). Disconnect fuel supply line at inlet side of fuel filter. Test fuel pressure. If test results are not 1.50 to 2.25 psi, replace fuel supply pump (Para 3-17). If test results are 1.50 to 2.25 psi, go to step 3. Step 3. Test fuel filter pressure drop at engine idle (650-700 rpm). Disconnect fuel supply line at outlet side of fuel filter. Test fuel pressure. If test results are not 1.50 to 2.25 psi, replace fuel filter (Para 3-16). If test results are 1.50 to 2.25 psi, go to step 4. Step 4. Test fuel return pressure at engine idle (650-700 rpm). Disconnect fuel return line at outlet side of fuel pump. Test fuel pressure. If test results are not 2.4 psi (16 kPa), fuel line blockage is indicated. Remove and replace fuel return lines (Para 3-17). If test results 2.4 psi (16 kPa), go to step 5. Step 5. Test coolant temperature after 10 minutes of operation. If coolant temperature is above 217°F (102°C), proceed to 4. ENGINE TEMPERATURE ABOVE NORMAL. If coolant temperature is below 180°F (820C), remove and test thermostat (Appen- dix F, Cooling System, Section 4.8). Refer to Appendix F, Continental Diesel Engine, Section 4.4, Section 4 to test thermostat. Replace thermostat as necessary. If coolant temperature is normal, go to step 6. 2-4