TM  10-3930-643-34 ENGINE,  FUEL,  EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 4-1. Engine,  Fuel,  Exhaust  and  Cooling  Troubleshooting.  (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION h. LOW  INTAKE  MANIFOLD  PRESSURE.  (cont) Step 5. Test crankcase pressure and engine cylinder compression, refer to paragraphs 4-1.k and 4-1.i. If crankcase pressure test does not meet specifications, refer to General  Support. If crankcase pressure is satisfactory and engine compression does not meet specifications, check for blown head gasket or cylinder head repair, refer to paragraph 4-4. i. ENGINE CYLINDER COMPRESSION TEST. 1. Start and run engine until normal operating temperature is obtained, refer to TM 10-3930-643-10. 2. Stop engine and remove fuel injectors, refer to paragraph 4-12. 3. Clean and remove foreign material from cylinder head fuel injector sealing 4. Install port on 5. Connect surfaces. compression  test  adapter,  DRO2-3031-10,  to fuel injector number one cylinder. adequate  cylinder  compression  gage  to  adapter. 4-10