TM-9-2815-220-24 Maintenance Manual for AVDS-1790-2CA AVDS-1790-DA and AVDS-1790-2DR Engines Download
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TM 9-2815-220-24 ENGINE ROUGH OPERATION 0014 00 MALFUNCTION 1: (Continued) Engine misfires (more noticeable at idle operation). PROBABLE CAUSE CORRECTIVE ACTION e. (Continued) No valve rocker clearance. (1) Locate faulty cylinder as follows: PROCEDURE OBSERVATION ANALYSIS Fuel "Shorting" Method: Check all cylinders, one at a time. Loosen fuel injector tube fitting at nozzle end sufficiently to allow fuel leakage. Note cylinder on which no change in engine operation occurs, knock disappears or decreases, and/or engine roughness or misfire still exists. Indicates faulty cylinder, defective nozzle, tight rocker arm, worn valve or hydrostatically damaged connecting rod. High Pressure Fuel Check: Remove one engine cover on each side of engine for access to fuel injector nozzle tube fittings. Crank engine with fuel switch "ON" or start engine and operate at idle speed. High-pressure fuel spray pulsations at nozzle fitting. Fuel injection pump action is normal. Loosen fuel injector tube fitting at nozzle end sufficiently to allow fuel leakage. No fuel spray pulsations noted at nozzle fitting. Fuel injection pump deficiency. Cylinder Compression Test Method: Perform Cylinder Compression Test (WP 0033, Cylinder Compression Test). Note cylinder with low pressure (below 330 psi at 140-180 cranking rpm). Indicates faulty cylinder, damaged rings, piston, valve, connecting rod or tight rocker arm (no valve clearance). PROBABLE CAUSE CORRECTIVE ACTION e. (Continued) No valve rocker clearance. (2) Adjust valve to proper clearance (WP 0034, Intake and Exhaust Valve Clearance Adjustment). (1) Locate faulty cylinder as above. f. Intake or exhaust valve failure (burned, worn or damaged). (2) Inspect, repair or replace valve and/or cylinder (WP 0133, Cylinder Assembly Replacement). WP 0014 00-2