Fuel Injector Test

Remove injection nozzles from engine. Check injectors for erosion (due to unfiltered air particles), carbon build-up, or Blue-colored tip (caused excessive engine heat). Replace any damaged injectors as necessary.
CAUTION: DO NOT allow test oil to be sprayed onto hands or fingers while testing. High pressure from nozzle spray can penetrate skin, which could cause blood poisoning.
Fill reservoir of Bosch Nozzle Pressure Tester (EFEP60H) with clean test oil. Connect nozzle and nozzle holder assembly to tester. Close pressure gauge valve. Quickly operate tester lever 8-10 times to bleed air from tester.
Open pressure gauge valve 1/4 turn. Slowly operate tester (1 pump/second), noting pressure required to open nozzle. Nozzle opening pressure should be 1885-2000 psi (132-140.6 kg/cm² ). Injectors with incorrect opening pressure should be replaced.
Slowly operate tester (1 pump/second), noting spray pattern of each nozzle. Spray should emerge at a 90° angle to nozzle tip, and should be in an even, finely atomized pattern. Replace any injectors that do not have correct spray pattern. A "whistle" sound, produced during testing, is a normal condition.
Slowly operate tester (1 pump/second) until pressure reading is 300 psi below normal opening pressure. Hold pressure at that point for 10 seconds. No fuel should drip from nozzle. If leakage occurs during 10 second period, replace injector.

NOTE: During this test procedure, a slight wetting of nozzle tip is normal.