ERRATIC ENGINE OPERATION (SURGE, MISFIRING, POOR GOVERNOR REGULATION) (cont)

TM 10-3930-638-24&P

3-4. FUEL SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

5. ERRATIC ENGINE OPERATION (SURGE, MISFIRING, POOR GOVERNOR REGULATION) (cont)

Step 10. Remove and inspect idle spring (para 4-3b; notify general maintenance).

a. If idle spring is broken or permanently set, replace (para 4-3b).

b. If idle spring is okay, proceed to step 11.

Step 11. Remove governor thrust sleeve and check for burrs and dirt (para 4-3b; notify general support

maintenance).

a. Remove burrs using crocus cloth; clean governor thrust sleeve as described in paragraph 4-3b.

b. If governor thrust sleeve checks okay, proceed to step 12.

Step 12. Check transfer pump parts for wear or damage (para 4-3b; notify general support maintenance).

a. If transfer pump parts are worn or damaged, replace (para 4-3b).

b. If transfer pump parts check okay, proceed to step 13.

Step 13. Remove fuel injection pump regulating piston and sleeve and inspect for burrs, corrosion, and

varnish accumulation (para 4-3b; notify general support maintenance).

a. If piston and sleeve are burred, corroded, or varnish accumulation is present, replace (para 4-3b).

b. If piston and sleeve check okay, proceed to step 14.

Step 14. Check delivery valve screw for tightness (para 4-3b; notify general support maintenance).

a. If delivery valve screw is loose, tighten (para 4-3b).

b. If delivery valve screw is tight, remove it. Then, remove delivery valve and inspect seat for

1) If seat is eroded, replace delivery valve (para 4-3b).

2) If seat is okay, reinstall and tighten delivery valve screw (para 4-3b) and proceed to step 15.

Step 15. Check delivery valve for cleanliness or improper installation (para 4-3b; notify general support

maintenance).

a. If delivery valve is dirty, clean or replace it (para 4-3b); if improperly installed, install

correctly (para 4-3 b).

b. If delivery valve is clean and properly installed, proceed to step 16.

Step 16. Disassemble fuel injection pump and check cam roller shoes for burrs; also check for freedom of

rotation, chipping, and abrasive wear patterns (para 4-3b; notify general support maintenance).

a. Replace cam roller shoes if burred, sticking, chipped or abrasive wear pattern observed

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