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

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 3. Disconnect and remove fuel injector return lines (para 3-6a).

Check return lines for clogged condition.

a. If fuel injector return lines are clogged, clean as described in paragraph 3-6a. After cleaning

return lines, recheck to ensure that all foreign matter has been removed, then reinstall (para 3-6a).

b. If fuel injector return lines are not clogged, proceed to step 4.

Step 4. Disassemble fuel injection pump and check automatic advance components (para 4-3b; notify

general support maintenance).

a. If automatic advance components are worn or damaged, replace and adjust (para 4-3b).

b. If automatic advance components are okay, proceed to step 5.

Step 5. Disassemble fuel injection pump and check governor linkage for binding, foreign matter, and burrs;

check metering valve for sticking condition (para 4-3b; notify general support maintenance).

a. If linkage is binding or burred, replace (para 4-3b); if foreign matter is present, remove; if

metering valve is sticking, replace (para 4-3b).

b. If linkage and metering valve check okay and no foreign matter present, proceed to step 6.

Step 6. Check that metering valve spring shim is installed (para 4-3b; notify general support maintenance).

a. If metering valve spring shim is not installed, install (para 4-3b).

b. If metering valve spring shim is installed, proceed to step 7.

Step 7. Disassemble fuel injection pump and check governor parts and linkage for wear, sticking condition, or

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

a. If governor parts and linkage are worn, sticking, or binding replace (para 4-3b).

b. If governor parts and linkage are okay, proceed to step 8.

Step 8. Remove governor spring and inspect (para 4-3b; notify general support maintenance).

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

b. If governor spring checks okay, proceed to step 9.

Step 9. Check governor linkage hook for correct adjustment (para 4-3b; notify general support maintenance).

a. If governor linkage hook is not adjusted properly, adjust as described in para 4-3b.

b. If governor linkage hook is adjusted properly, proceed to step 10.

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