ENGINE IDLES IMPERFECTLY

TM 10-3930-638-24&P

3-4. FUEL SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

6. ENGINE IDLES IMPERFECTLY (cont)

Step 4. (cont)

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, proceed to step 5.

Step 5. 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 6.

Step 6. Remove and inspect idle spring (para 4-3b; notify general support maintenance).

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

b. If idle spring is okay, proceed to step 7.

Step 7. Check governor linkage hook for proper adjustment (para 4-3b; notify general support maintenance).

a. If governor hook is not properly adjusted, adjust (para 4-3b).

b. If governor hook is properly adjusted, proceed to step 8.

Step 8. Disassemble automatic advance components and inspect (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 9.

Step 9. 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 10.

Step 10. 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 11.

Step 11. Inspect governor linkage for breaks or cracks (para 4-3b; notify general support maintenance).

a. If governor linkage is broken or cracked, replace and adjust para 4-3b).

b. If governor linkage checks okay, proceed to step 12.

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