TM 10-3930-638-24&P 3-3. ENGINE TROUBLESHOOTING (cont) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION 7. ENGINE COMPRESSION TEST Remove fuel injectors, and clean fuel injector bores  in  cylinder  head  (para  3-6b). Install  D-558  compression  gage  adapter (FSCM 05083 P/N 70-314) in fuel injector bore at No. 4 cylinder, and secure with clamp assembly  and  spacer  as  shown. Connect compression gage (FSCM 10988 P/N CD-504) to adapter, crank engine with starter, and record gage reading. Depress vent button to relieve gage pressure and repeat test. NOTE Engine cranking speed must be approximately 200 RPM for reliable test results. If necessary, charge batteries to maintain proper  cranking  speed. Disconnect compression gage and adapter from No. 4 cylinder and repeat above test at remaining three  cylinders. The gage reading for any one cylinder at a given altitude above sea level must not be less than the minimum  listed  in  the  chart  below. In  addition,  the  difference  between  gage  readings  for  the  highest  and  lowest  cylinders  should  not  exceed 25  PSIG. CYLINDER COMPRESSION TEST CHART Minimum  Compression Altitude Above Pressure at 200 RPM Sea Level (PSIG) (Feet) 400 0 384 1,000 360 2,500 320 5,000 280 7,500 240 10,000 3 - 5