Fuel System/Fuel Injection Nozzles Spray pattern test centerline of the nozzle body, but should be distributed. For a better check, place a piece of paper or cardboard at a suitable distance below the nozzle and check the appearance of the damp circular spots made by the fuel. Deviations from the regular spray pattern or angle may be due to the complete or partial clogging of a nozzle orifice. In this case the fuel issues in a jet rather than in a fine spray. Close gauge shut-off valve and operate the pump lever at 60 strokes per minute. If the fuel injection nozzle is working properly, the fuel should issue through all nozzle orifices in a fine, evenly shaped spray cone.
This spray cone is inclined from the CD,3274,G40,41 -19-01FEB94 Chatter test characteristic “chatter” should be heard. If this is not the case, the nozzle valve may be bent or tight in its guide because of the lacquer deposits which have accumulated. This can be corrected only by disassembling the nozzle. Make sure nozzle orifices are free. When working pump of fuel injection nozzle tester at 60 strokes per minute (gauge shut-off valve closed), a definite CD,3274,G40,42 -19-01FEB94 CTM3274 (01JUL99) 40-61 Saran Liter Engines 060799 PN=306 Checking valve stem and guide wear constant and observe how much fuel leaks out of the nozzle return end.
After the first drop has formed, Connect fuel injection nozzle to the nozzle tester with count the drops for 30 seconds; there should be 3 to the tip raised a little higher than its opposite end. 10 drops. Cover the tip and pump the tester to a pressure of 10300 kPa (103 bar; 1500 psi). Keep the pressure CD,3274,G40,43 -19-01FEB94 40 Opening pressure test pressure up to the point where the pressure gauge 61 needle falls rapidly. This point (take reading) is the NOTE: Absolute opening pressure is less important nozzle valve opening pressure (minimum pressure than equal opening pressure of all nozzles. see “Specifications”). Max. permissible variation see Specifications.
If spray pattern, leakage test, and valve wear test Close gauge shut-off valve and actuate the pump (see below) are good but the opening pressure test is several times to allow the nozzle valve to seat unsatisfactory, adjust opening pressure as described properly. Open gauge shut-off valve. Pump the under “Adjustment”. CD,3274,G40,44 -19-01FEB94 Opening pressure test pressure up to the point where the pressure gauge needle falls rapidly. This point (take reading) is the NOTE: Absolute opening pressure is less important nozzle valve opening pressure (minimum pressure than equal opening pressure of all nozzles. see “Specifications”). Max. permissible variation see Specifications.
If spray pattern, leakage test, and valve wear test Close gauge shut-off valve and actuate the pump (see below) are good but the opening pressure test is several times to allow the nozzle valve to seat unsatisfactory, adjust opening pressure as described properly. Open gauge shut-off valve. Pump the under “Adjustment”. CD,3274,G40,44 -19-01FEB94 61