ENGINE IDLES IMPERFECTLY (cont)

TM 10-3930-638-24&P

3-4. FUEL SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

6. ENGINE IDLES IMPERFECTLY (cont)

Step 12. Check that hydraulic head screws are tight or are not missing (para 4-3b; notify general support

maintenance).

a. If hydraulic head screws are not tight or are missing, tighten and/or install (para 4-3b).

b. If hydraulic head screws are tight and not missing, proceed to step 13.

Step 13. Check rotor and hydraulic head assembly (in plunger area) for wear (para 4-3b; notify general support

maintenance).

a. If rotor and hydraulic head are worn in plunger area, replace (para 4-3b).

b. If rotor and head are okay, proceed to step 14.

Step 14. Remove delivery valve and inspect for dirt or improper installation (para 4-3b; notify general support

maintenance).

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

b. If delivery valve is clean and properly installed, proceed to step 15.

Step 15. Remove plungers and inspect for burrs, corrosion or varnish accumulation (para 4-3b; notify general

support maintenance).

Replace plungers if burred, corroded, or varnish accumulation is present (para 4-3b).

7. ENGINE DOES NOT DEVELOP FULL POWER OR SPEED

Step 1. Check throttle arm installation and adjustment (para 2-15i).

a. If throttle arm installation is not correct or if adjustment is not correct, correct installation and

adjust as described in paragraph 2-15i.

b. If throttle arm installation is correct and if adjustment is correct, proceed to step 2.

Step 2. Check governor linkage for proper adjustment (para 4-3b; notify general support maintenance).

a. Adjust governor linkage (para 4-3b).

b. If governor linkage adjustment is okay, proceed to step 3.

Step 3. Check governor no-load governed speed for proper adjustment (para 3-5a).

a. If governor no-load governed speed is not adjusted properly, adjust as described in paragraph 3-5a.

b. If governor no-load governed speed is adjusted properly, proceed to step 4.

Step 4. Remove inlet strainer and check for clogged condition (para 4-3b; notify general support maintenance).

a. If inlet strainer is clogged, either clean or replace strainer (para 4-3b).

b. If inlet strainer is not clogged, proceed to step 5.