Cleaning and Testing

NOTE: Poor injector performance can often be corrected by flushing and testing injector using injector tester.

- check injector visually for rust
- if rust is seen in injector inlet, replace injector
- if no rust, proceed with test





- using suitable container under injector to catch spray, connect injector loosely to tester pressure line
- turn pressure valve (arrow) counterclockwise to open

WARNING: Fluid used in tester (Shell Mineral Spirits 135) is flammable. DO NOT SMOKE or have anything in area that can ignite fuel or fumes

CONTAMINATION TEST
- open union nut
- bleed pressure line by operating lever several times
- tighten union nut
- operate hand lever slowly (approx. 2 strokes/sec) with hand valve open
- specification: approximately 1.5 to 2.0 bar (21.8 to 29.0 psi)

- if pressure does not build up, injector has leakage (e.g. foreign object(s) lodged between seat). If this is the case, proceed to bleeding of injector and repeat contamination test
- if after bleeding, pressure is restored; continue testing

If NO
- replace injector

INJECTOR BLEEDING PROCEDURE





- close hand valve on test fixture
- operate lever quickly, approximately 20 to 30 strokes
- injector is bled when chatter frequency stabilizes

OPENING PRESSURE
- open hand valve
- while slowly moving lever (approx. 2 strokes/sec) read opening pressure on gauge
- specification: 3.0 to 4.1 bar (43.5 to 59.5 psi)

LEAK TEST (HAND VALVE OPEN)
- using previously established opening pressure as a reference; slowly increase pressure to 0.5 bar (7.3 psi) below that value, but never less than 2.8 bar (40.6 psi)
- a droplet may form at the injector tip within 15 seconds; however, if the drop falls off, replace injector

CHATTER - SPRAY PATTERN TEST
- close hand valve
- purge injector by operating lever several times (approx. 2 strokes/sec)
- reduce rate to approx. 1 stroke/sec
- injector must chatter

NOTE: Spray pattern should be conical and well atomized. A one sided spray pattern within the spray angle of approximately 35° (well atomized) is acceptable.

If droplets form by injector tip
- replace injector

If injection forms a straight stream
- replace injector

If injection forms a steady stream (non atomized)
- replace injector

CAUTION: Before installing new injector, flush new injector in tester to remove any foreign matter that might have entered injector from packing or shipping container