Table 14-2. Fuel DeliveryPump rpmDeliveryPressure900113-118 mm360-65 psi (hold)600121-126 mm345-50(high idle) 91815-17 mm3l(3) Start stand at lowest speed and check forclockwise rotation.Move throttle to full-load posi-tion. When transfer pump picks up suction, allowfuel to bleed for several seconds from loosened con-nector screws.Likewise, allow fuel to bleed fromloosened injection line nuts. Tighten securely.(4) Operate Pump at 500 rpm for 10 minutes.Dry off completely with compressed air. Observefor leaks and correct as necessary. Back out thehigh idle stop screw and torque screw.NOTEThe inlet to the transfer pump shouldnever be pressurized during bench testing.(5) Close valve in supply line -transfer pumpmust pull at least 18 inches hg at 200 rpm.If it does not, check for air leaks on suction side ormalfunction of end plate and transfer pump parts.(6) Fill graduates to bleed air from test standand to wet glass.(7) Observe return oil. Return should be atrate of 100-450 cc/minute at 35 psi transfer pumppressure.CAUTIONUnder no circumstances should 130 psi beexceeded, as the pump will be damaged.(8) Operate at the 900 rpm with wideopen throttle and observe transfer pump pressure.Adjust pressure-regulating spring plug to raise orlower transfer pump pressure.(9) Check for minimum delivery at crank-ing speed of 75 rpm.The delivery rate shouldbe a minimum of 65 mm3/s at a minimum of 8 psi.(10) Operate at 918 rpm. and adjust high idlescrew to obtain 20-25 percent of full-load fueldeliver y.(11 ) Adjust the low idle screw, if used, toa low idle delivery of 10-12 cc/1000 strokes at500 rpm.(12) Check the cam position at specified pointsin the speed range given in table 14-2. Attain allspeeds by first running at a higher rpm, then reduceto normal operation speed. Adjust trimmer screw,or shim, as required, to obtain proper advanceoperation.Each mark on the timing window is14-54 Change 12 pump degrees (4 engine degrees).(13) Record fuel delivery at check points shownin table 14-2.NOTERoller settings should not be readjustedon the test bench. Micrometer and dialindicator settings provide more consis-tent, accurate results in performance.Variations in test benches, nozzles,lines, and fuels in different areas some-time result in inaccurate flow readings.(14) Recheck delivery at 900 rpm checkpoint.(15) Check governor cutoff at 950 rpm.(16) Speed droop device test and adjustment.(a) After normal pump test, check full-loadgovernor regulation by moving the throttle lever tow-ard the closed position until the pump is “on governor”at full-load speed. 1800 (60 Hz), 1500 (50 Hz), 2000(400 Hz). This will be indicated by a difference in de-livery sound and a slight reduction of fuel delivery(1-2cc/1000 strokes) when a “draw” is taken into thegraduates. Hold the throttle in this position with thestandard vernier rack positioner supplied with mosttest benches. Do not position throttle by means ofhigh- speed adjusting screw.(b) Increase test stand speed. Record speedwhere fuel delivery falls to 116-120 cubic millimetersper stroke (1500 rpm or 50 Hz) or 114-118 cubic milli-meters per stroke (1800 rpm or 60 Hz). This speed isknown as no-load speed and should not be higher thanthe percentage or the high idle speed 1836 rpm (60 Hz),1545 rpm (50 Hz). If, for example, the unit operatesat 1500 rpm full-load and 3 percent regulation is re-quired, no-load speed will be:1500 x 0.03=451500 +45 = 1545At 1545 rpm, the pump should not deliver more than116-120 cubic millimeters per stroke at 50 Hz;114-118 cubic millimeters per stroke at 60 Hz.(c) If high idle, no load speed, as describedabove, is too low, adjust by means of the knurledknob at the rear of the pump housing. This is thedroop adjustment.The knob should be turned clock-wise to raise the no-load speed 1836 rpm (60 Hz);1545 rpm (50 Hz).
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business