TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download
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• TM 9-2815-220-34 Section II. TROUBLESHOOTING 2-7. Purpose of Troubleshooting Information in this chapter is for use of Direct Support and General Support maintenance per- sonnel. It provide� the instructions to supporting maintenance personnel for corrective action. a. Prevent Damage. Operation of a malfunction- ing or deadlined vehicle or engine without a pre- liminary examination can cause further damage to the engine and possible injury to personnel. By careful inspection and troubleshooting, such dam- age and injury can be avoided. In addition, the cause of faulty operation can often be determined without extensive disassembly. b. Preccmtions by Inspectfon. The inspections are to be performed before attempting to operate the vehicle. These inspections are mainly to detennine the condition and to take precautions to prevent further damage. c. Troubleshooting While Moimted. The trouble- shooting performed while the engine is mounted in the vehicle is included in this troubleshooting sec- tion. The procedures for troubleshooting vehicle components and systems related to engine opera- tion are also included. d. Troubleshooting Engine Only. If the engine only is received, inspection should be performed to verify the diagnosis made while the engine was installed in the vehicle. This insp ection, to uncover further defects or to determine malfunction, is im- portant as it is the only means for determining the trouble without completely disassembling the en- _gine. 2-8. General Instructions 1his chapter contains .inspection a11d troubleshoot- ing procedures to be perrmed while a malf unc- tioning enne is still mounted the vehicle and after jt has been removed. Those procedures which apply only with the engine or power pack removed om the vehicle are jndicated with the symbol*. The procedures are presented jn paragraph 2-9, Troubleshooting Procedures, and paragraph 2-10, Diagnosti c Tests. Troubleshooting procedures r I t he c lean air package for the models AVDS-1790-2CA, and AVDS-1790-2DA are presellted in Chapter 4. 2-9. Troubleshooting Procedures A table of contents is provided for this section. When a malfunction occurs, it can be related to a specific engine, component or engine system ab- normal operation. The index is so classified to as- sist in locating the appropriate troubleshooting item. Probable causes are listed for each item. The causes are listed in order of most frequent occurr- ence or in logical sequence for ease and time of accomplishment. Corrective actions are listed for each probable cause. The actions are in logical sequence for ac- complishment. When detailed instructions are re- quired to accomplish the corrective action, re- ferences are made to the appropriate technical manual. When diagnostic testing is necessary be- fore final corrective action can be determined, re- ference is made to the approp1iate diagnostic tests in table 2-3. 2-10. Diagnostic Tests This section contains diagnostic test descriptions which are referenced in table 2-2, Troubleshooting Procedures. These tests provide analysis for the purpose of determining further corrective action required to eliminate a malfunction. A table of contents is provided to assist in locating the re- quired diagnostic test. Trcmbleshooti Procedures Contents for table 2-2 Item No. Malfwictior1 1. Engine Fails to Crank l·l Engine will not crank: 1-2 Starter engages but engine does not crank: 1-3 Starter drive spins, but engine does not crank: 2. Engine Cranks Too Slow 2-1 Cranking speed too slow r starting: 3. Engine Fails to Start At Normal Cranking Speed 3.1 Cylinders not fi1;ng: 3·2 Cylinders partially fi1fog: 4. Engine Low Idle Abnormal Operation 4·1 Low idle speed too low: 4·2 Low idle speed erratic: 4-3 fislires at idle: 5. Engine High Idle (No Load) Abnormal Operation 5-1 High idle speed too low: 5-2 High idle speed too high: Chan 3 2·10.7