车辆工程专业英语PPT课件-UNIT-3--FUEL-INJECTION-SYSTEMS-TEXT-

No.10039UNIT3FUELINJECTIONSYSTEMSTEXTCTroubleshootingtheEFISystemPROFESSIONALENGLISHNo.10039UNIT3FUELINJECTIONSYSTEMSTEXTBTroubleshootingtheEFISystemEngineConditionElectricalSystemIntakeAirLeakageTranslationTechniques(3)—词类转换本次课学习内容No.10039本次课学习目标掌握EFI系统的故障诊断方法掌握常用术语，了解相关术语掌握翻译技巧，提高翻译能力NEWWORDStroubleshoot['trʌbl∫u:t]v.排除故障tightness['taitnis]n.坚固，紧密integrity[in'tegriti]n.完整性concentrate['kɔnsəntreit]v.集中tune-up['tju:n-ʌp]n.调整tackle['tækl]v.捉住，从事，对付dipstick['dipstik]n.机油尺canister['kænistə]n.罐purge[pə:ʤ]n.&v.排污，排空，清除clog[klɔg]v.堵塞，妨碍；n.障碍（物）faulty['fɔ:lti]a.报废的，无用的，出故障的，vent[vent]v.通风crankcase['kræŋkeis]n.曲轴箱probe[proub]n.探索，探针，探头，取样器meter['mi:tə]v.计量，测量proceed[prə'si:d]v.（着手，继续）进行symptom['simptəm]n.症状，征兆continuity[kɔnti'njuiti]n.连通，连续性leakage['li:kiʤ]n.泄漏hesitation[hezi'tei∫ən]n.迟缓，断续工作surge[sə:ʤ]n.(发动机）喘振，波动，颤抖clamp['klæmp]n.夹（具，板，子），夹紧装置；卡箍（子）diaphragm['daiəfræm]n.膜片soapy['soupi]a.圆滑的，滑腻的squirt['skwə:t]v.喷出gasket['gæskit]n.衬垫styrofoam['stairəfoum]n.聚苯乙烯泡沫（塑料）vaporcanister蒸气罐canisterpurgevalve炭罐排污阀，炭罐清空阀falseair从窑炉各处缝隙吸入（炉内）的空气vacuumhose真空软管brakebooster制动助力器leakdetector检漏器,检漏剂startby+ing打…开始，（一）开始就（做）strangeasitmaysound听[说]起来也许奇怪PHRASESANDEXPRESSIONSTroubleshootingtheEFISystemThebasicfunctionofthefuelinjectionsystemistosupplyandmeterthecorrectamountoffueltotheengineinproportiontotheamountofairbeingdrawnintotheenginetoachievetheoptimumair-fuelmixture.Anyproblemswithelectricalconnections,airintakesensing,orfuelsupplywillcausepoorrunning.Anytroubleshootingshouldbeginwithsimpleandeasychecksofthetightnessofsystemwiringandtheintegrityoftheairintakesystem.Proceedfromtheretomoreinvolvedtroubleshooting.Generally,fuelinjectionproblemsfallintooneoffoursymptomcategories:coldstart,coldrunning,warmrunning,andhotstart.Warmrunningisthemostbasiccondition.Beforetroubleshootingaconditioninanyothercategory,makesurethatthesystemisworkingwellandisproperlyadjustedforwarmrunning.Tosimplifytroubleshooting,concentrateonthesensorsandcomponentsthatadaptfuelmeteringforaparticularcondition.Forexample,iftheenginewillnotstartwhencold,thecomponentsresponsibleforcoldstartenrichmentaremostlikelyatfault,andshouldbetestedfirst.EngineConditionThefuelinjectionsystemissettooperateonanenginethatisingoodoperatingcondition.Becausethefuelinjectionsystemisoftenthenewitem,somepeoplewastetimecheckingitwhenthetroublemaybewithbasicengineoperation.Itisagoodideatousethecarmanufacturer'sshopmanualtoperformatune-up,andtocheckthefollowingsystemsbeforetacklingthefuelinjectionsystem.1.Ignitionsystem.Checktiming,includingadvanceandretardcontrol,ignitioncomponentsandsparkquality.2.Electricalsystem.Checkbatteryconditionandconnections,andalternatorandvoltageregulator.3.Airintakesystem.Checktheairfilter,PCVandcrankcaseconnections,andtheevaporativeemissionconnections.Alooseoil-fillercapordipstickcanleanthemixturebyadmittingextraairtotheintakemanifoldthroughthePCVvalve.Thevaporcanistercanenrichthemixturebyadmittingfuelvaporsintotheintakemanifoldthroughthecanisterpurgevalve.4.Fuelsystem.Acloggedfiltermayreducefuelflow.Afaultyfuelfillercaportankventvalvemaycreategastankvacuumandreducefuelflow.Besurethecarhasfuelinthetank.5.Mechanicaloperation.Checkgradeandconditionofcrankcaseoil,compression;valvetiming,andtheexhaustsystem.ElectricalSystemWheneverworkingonthewiring,takecaretoavoidbendinganypinsorconnectors.Useflatpinprobesifpossible.Insertingtheprobesofavoltmeterorohmmetertoofarintoawiringconnectormayspreadthecontactsandcreateanewproblem.RelaySetandSystemPowerAfaultyrelaysetmaypreventthefuelpumpfromoperating,orpreventpowerfromreachingthecontrolunit.Removetheconnectorfromtherelayset,andwiththeignitionon,checkforvoltageattheterminalsoftheconnector.Ifthereisvoltage,thentherelaysetisprobablyfaulty,butcheckthecontinuityofthewiringtothepumpandcontrolunit.WiringHarness,ConnectionsandGroundsStrangeasitmayseem,thecomponentsofpulsedsystemsusuallygivelesstroublethanthewiringharnessesandconnectorsthatlinkthem.Evensmallamountsofcorrosionoroxidationattheconnectorterminalscaninterferewiththesmallmilliampcurrentsthatsignalthesystemtooperate.Thisproblemiscompoundedbytheseveralgroundpathsprovidedtoinsurereliableoperation.Morethanoneownerofabadcontrolunitorcomponenthaspaidforreplacementwhentheproblemwasinthewiring.Inmanycases,cleaningconnectorsandgroundsmaysolvefuelinjectionproblems.Identifyallwiringconnectorsandgroundlocationsusingtheshopmanual.Thegroundlocationsshouldbesecureandfreefromcorrosionorgreaseandoil.Withtheignitionoff,disconnectthewiringconnectors,includingthecontrolunitconnector,andalsocheckthemforcorrosionordirt.Simplydisconnectingandreconnectingtheconnectorswillcleanupthecontacts,butyoucanalsouseacontactcleanerdesignedforelectroniccomponents.Don'tforgettocheckforbreaksorshortsinthewiringharness.Afuelinjectorortemperaturesensormaybegood,butthewiringtothecontrolunitmaybefaulty.Youcancheckthisusinganohmmeter.Withtheignitionoff,disconnectthecontrolunitconnectorandtestforcontinuitybetweenthecomponentterminalsandthecorrespondingterminalsatthecontrolunitconnector.Areadingofzer