TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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counter reading at each 200 rprn increment increase, beginning at 600 rpm and continue through to 2600 rpm. (m) Reduce speed to 600 rpm and re- check counter reading. If this reading does not check with the original repeat the test. Check the readings taken at each 200 rpm increase against similar points on the approved advance unit curve, figure 6-200. If the recorded advance readings fall within the prescribed limits on the curve, the test is complete. If the advance readings do not meet the curve limits, proceed with step (p) below. (n) Turn speed regulator control to zero (0), figure 6-199b, to reduce speed and counter switch, motor switch, and master switch handle to the “OFF” position. Note. Injector pump advance assembly will be hot following test. Operator should wear gloves when removing unit from test stand. (o) Loosen fasteners and remove cover. Remove bearing caps and remove unit from bench. Remove oil transfer shaft. Place injector advance pump assembly on oil drain tray with small gear end up. Place advance assembly in a clean dirt-free container, preferably a polyethylene bag, for storage after draining and cooling. Figure 6-200. Fuel injector advance unit curve. (p) Repeats steps (h) through (m) to check previous readings. If advance assembly fails to pass the test, it must be adjusted. Note whether advance assembly advances too soon or too late. Either condition can normally be corrected by rotating the advance flyweight adjusting ring. Note. The advance assembly should be retarded slightly if the advance varies more than 2 degrees at 300 rpm when the oil pressure drain button is depressed. This variance indicates the mechanical retard stop is not in phase with the hydraulic valve. (r) Push speed control stop switch to disengage eddy current clutch. Turn counter, motor, and motor starter off. (s) Loosen fasteners and remove cover. Remove two cotter pins, and loosen the two slotted nuts enough to permit adjusting ring rotation. See figure 6-201. Note. Do not turn the adjusting ring more than 1 / 16 of an inch during any one ad- justment. 6-168