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. 3-15