TM 10-4320-315-24
Table 3-1. Direct Support Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. ENGINE CRANKS, BUT DOES NOT START.
Step 1. Check cylinder compression.
Adjust rocker arm assembly (para. 2-55).
Remove injector nozzles (para. 2-50).
Install compression gauge in one nozzle hole.
Crank engine over and note compression.
Remove compression gauge from cylinder already checked and install in the other cylinders.
Crank engine over and note compression.
Compression of cylinders should be approximately 319-362 psi (2199-2496 kPa) and should
be within 15 percent of each other. If not within specification, refer to general support
maintenance.
NOTE
These compression figures may vary considerably depending on cranking speed, altitude
and ambient temperature. The most reliable indication of a properly functioning engine is
one in which the compression of each cylinder is within 10 psi (68.94 kPa) of the other and
one in which the addition of a small amount of motor oil in the cylinder does not significantly
increase either the compression or difference in compression between the cylinders.
Step 2. Check timing of fuel injection pump (para. 3-18).
2. LOW POWER IN THE ENGINE.
Step 1. Check for blown or leaky head seals.
Replace defective head seals (para. 3-30).
Step 2. Check for poor compression. Refer to malfunction 1, step 2.
If poor compression, refer to general support maintenance.
Step 3. Check timing of fuel injection pump (para. 3-18).
3-2
