【電(dian)噴柴(chai)油機(ji)(ji)維(wei)修(xiu)】電(dian)噴柴(chai)油機(ji)(ji)常見故(gu)障(zhang)處理 電(dian)噴柴(chai)油機(ji)(ji)維(wei)修(xiu)

電噴柴油機常見故障處理

常見電噴柴油發動機的典型故障主要出在傳感器上。如傳感器工作不正常時對發動機微機控制系統工作影響很大。產生故障的原因主要是電控系統的元件性能發生變化或不穩定。電控柴油發動機的(de)(de)(de)(de)(de)工(gong)作主要(yao)是(shi)依靠電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)單元(ECU)來控(kong)(kong)(kong)(kong)(kong)(kong)制發(fa)(fa)動(dong)(dong)機在(zai)(zai)各(ge)種(zhong)工(gong)況條件下的(de)(de)(de)(de)(de)供油(you)量，而電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)單元控(kong)(kong)(kong)(kong)(kong)(kong)制的(de)(de)(de)(de)(de)供油(you)量多(duo)少，必(bi)(bi)須(xu)與發(fa)(fa)動(dong)(dong)機的(de)(de)(de)(de)(de)工(gong)況相(xiang)匹配，這(zhe)種(zhong)匹配關(guan)系(xi)(xi)(xi)必(bi)(bi)須(xu)是(shi)電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)系(xi)(xi)(xi)統(tong)狀況與發(fa)(fa)動(dong)(dong)機實(shi)際狀況相(xiang)吻(wen)合的(de)(de)(de)(de)(de)關(guan)系(xi)(xi)(xi)。比如在(zai)(zai)控(kong)(kong)(kong)(kong)(kong)(kong)制發(fa)(fa)動(dong)(dong)機節氣門(men)使發(fa)(fa)動(dong)(dong)機在(zai)(zai)經濟車速運(yun)轉時，這(zhe)時反(fan)映(ying)的(de)(de)(de)(de)(de)是(shi)發(fa)(fa)動(dong)(dong)機部分負(fu)荷(he)工(gong)況，電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)系(xi)(xi)(xi)統(tong)中各(ge)種(zhong)傳感器所提供給(gei)電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)單元的(de)(de)(de)(de)(de)反(fan)映(ying)發(fa)(fa)動(dong)(dong)機部分負(fu)荷(he)狀態(tai)的(de)(de)(de)(de)(de)參(can)(can)數，也應是(shi)符(fu)合發(fa)(fa)動(dong)(dong)機在(zai)(zai)部分負(fu)荷(he)狀態(tai)下的(de)(de)(de)(de)(de)數據，這(zhe)些標志發(fa)(fa)動(dong)(dong)機負(fu)荷(he)狀態(tai)的(de)(de)(de)(de)(de)參(can)(can)數，必(bi)(bi)須(xu)是(shi)與要(yao)求(qiu)(qiu)發(fa)(fa)動(dong)(dong)機達(da)到的(de)(de)(de)(de)(de)工(gong)況狀態(tai)相(xiang)吻(wen)合，若有一(yi)項參(can)(can)數不能(neng)達(da)到實(shi)際要(yao)求(qiu)(qiu)數值，這(zhe)時發(fa)(fa)動(dong)(dong)機轉速也就不能(neng)提升到相(xiang)對應的(de)(de)(de)(de)(de)轉速，這(zhe)種(zhong)匹配關(guan)系(xi)(xi)(xi)是(shi)發(fa)(fa)動(dong)(dong)機電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)系(xi)(xi)(xi)統(tong)能(neng)否滿(man)足實(shi)際要(yao)求(qiu)(qiu)的(de)(de)(de)(de)(de)一(yi)種(zhong)基礎(chu)關(guan)系(xi)(xi)(xi)，也是(shi)發(fa)(fa)動(dong)(dong)機電(dian)(dian)(dian)(dian)控(kong)(kong)(kong)(kong)(kong)(kong)系(xi)(xi)(xi)統(tong)能(neng)否按(an)照人(ren)的(de)(de)(de)(de)(de)意(yi)愿工(gong)作的(de)(de)(de)(de)(de)基本保證(zheng)。

另外，電(dian)控(kong)(kong)(kong)(kong)單元在控(kong)(kong)(kong)(kong)制發動機(ji)工(gong)作的(de)過程中，它所接(jie)受的(de)各種(zhong)傳(chuan)(chuan)感器信(xin)(xin)(xin)號(hao)是人(ren)們給定的(de)范(fan)圍(wei)(wei)，而(er)電(dian)控(kong)(kong)(kong)(kong)系統(tong)(tong)的(de)自診(zhen)斷系統(tong)(tong)功(gong)能就(jiu)是判斷這(zhe)(zhe)些傳(chuan)(chuan)感器的(de)信(xin)(xin)(xin)號(hao)是否(fou)超(chao)出(chu)(chu)了這(zhe)(zhe)個范(fan)圍(wei)(wei)，只(zhi)有(you)信(xin)(xin)(xin)號(hao)超(chao)出(chu)(chu)規定范(fan)圍(wei)(wei)后，自診(zhen)斷系統(tong)(tong)才(cai)能知道這(zhe)(zhe)種(zhong)信(xin)(xin)(xin)號(hao)不(bu)能作為控(kong)(kong)(kong)(kong)制信(xin)(xin)(xin)號(hao)使用，這(zhe)(zhe)時自診(zhen)斷系統(tong)(tong)才(cai)能確(que)定系統(tong)(tong)中有(you)故(gu)障，才(cai)能有(you)故(gu)障記憶，而(er)給出(chu)(chu)故(gu)障代碼(ma)(ma)。若信(xin)(xin)(xin)號(hao)沒有(you)超(chao)出(chu)(chu)給定范(fan)圍(wei)(wei)，但卻(que)與實際情況有(you)較大的(de)偏差，這(zhe)(zhe)種(zhong)不(bu)準(zhun)確(que)信(xin)(xin)(xin)號(hao)仍會使電(dian)控(kong)(kong)(kong)(kong)單元按(an)照提供的(de)不(bu)準(zhun)確(que)信(xin)(xin)(xin)號(hao)控(kong)(kong)(kong)(kong)制發動機(ji)工(gong)作，從而(er)造成(cheng)發動機(ji)產生(sheng)故(gu)障現象，而(er)自診(zhen)斷系統(tong)(tong)不(bu)能給出(chu)(chu)故(gu)障代碼(ma)(ma)，即為控(kong)(kong)(kong)(kong)制系統(tong)(tong)產生(sheng)軟故(gu)障的(de)根本原因。

常見電噴柴油機電控系統(tong)的(de)典型(xing)故障原(yuan)因及診(zhen)排方法(fa)如下：

怠速開關不閉合故障

怠(dai)速觸點斷開(kai)(kai)，壓力傳感器ECU便判(pan)定發動機處(chu)于部分負荷狀態。此時(shi)ECU根據空氣(qi)流(liu)量(liang)計和曲(qu)軸(zhou)轉(zhuan)(zhuan)(zhuan)速信號確(que)定噴(pen)(pen)油量(liang)。而此時(shi)發動機卻是在怠(dai)速工況下(xia)(xia)工作(zuo)，進(jin)氣(qi)量(liang)較少，造成混(hun)合氣(qi)過濃(nong)，轉(zhuan)(zhuan)(zhuan)速上(shang)升(sheng)。當ECU收到氧傳感器反饋的(de)(de)(de)“混(hun)合氣(qi)過濃(nong)”信號時(shi)，減(jian)少噴(pen)(pen)油量(liang)，增加怠(dai)速控(kong)制閥的(de)(de)(de)開(kai)(kai)度，又(you)(you)造成混(hun)合氣(qi)過稀。使轉(zhuan)(zhuan)(zhuan)速下(xia)(xia)降。當ECU收到氧傳感器反饋的(de)(de)(de)“混(hun)合氣(qi)過稀”信號時(shi)，又(you)(you)增加噴(pen)(pen)油量(liang)，減(jian)小怠(dai)速控(kong)制閥的(de)(de)(de)開(kai)(kai)度，又(you)(you)造成混(hun)合氣(qi)過濃(nong)，使轉(zhuan)(zhuan)(zhuan)速上(shang)升(sheng)。

診斷方(fang)法：怠速時打(da)開空調，打(da)方(fang)向(xiang)盤，發動機轉速不(bu)升高，可證明是(shi)此故(gu)障。故(gu)障排(pai)除：對節氣(qi)門位(wei)置傳感器進行(xing)調整、修復或(huo)更(geng)換。

怠速控制閥(ISC)故障

電噴發動機的正確怠速是通過電控怠速控制閥來保證的。ECU根據發動機轉速、溫度、節氣門開關及空調等信(xin)號，通過(guo)運算對怠(dai)(dai)速(su)(su)控制(zhi)(zhi)閥(fa)進(jin)行調(diao)節。當怠(dai)(dai)速(su)(su)轉速(su)(su)低(di)(di)于(yu)設(she)定轉速(su)(su)值時，電(dian)腦(nao)指令(ling)怠(dai)(dai)速(su)(su)控制(zhi)(zhi)閥(fa)打開(kai)進(jin)氣旁通道或直接加大節氣門的(de)開(kai)度(du)，使(shi)進(jin)氣量增加以提高發(fa)動機怠(dai)(dai)速(su)(su)。當怠(dai)(dai)速(su)(su)轉速(su)(su)高于(yu)設(she)定轉速(su)(su)值時電(dian)腦(nao)便指令(ling)怠(dai)(dai)速(su)(su)控制(zhi)(zhi)閥(fa)關(guan)小進(jin)飛旁通道，壓力傳感器使(shi)進(jin)氣減小，降低(di)(di)發(fa)動機轉速(su)(su)。由于(yu)油污、壓力傳感器積炭造成(cheng)怠(dai)(dai)速(su)(su)控制(zhi)(zhi)閥(fa)動作(zuo)滯澀或卡死(si)，節氣門關(guan)閉不到位(wei)等原因，使(shi)ECU無法對發(fa)動機進(jin)行正確地怠(dai)(dai)速(su)(su)調(diao)節，造成(cheng)怠(dai)(dai)速(su)(su)轉速(su)(su)不穩。

診(zhen)斷方法：檢(jian)查怠(dai)(dai)速(su)控制(zhi)閥的動作聲音，若無動作聲即怠(dai)(dai)速(su)控制(zhi)閥出現故障。故障排除：清洗或(huo)更換怠(dai)(dai)速(su)控制(zhi)閥，并(bing)用專用解(jie)碼器(qi)對怠(dai)(dai)速(su)轉(zhuan)速(su)進行基(ji)本設定(ding)。

進氣管路漏氣故障

壓力傳(chuan)感器(qi)由(you)發(fa)動(dong)機的(de)愈速(su)穩定(ding)控(kong)制原(yuan)理可知(zhi)，在正常情(qing)況下，怠速(su)控(kong)制閥的(de)開度(du)與進(jin)氣(qi)(qi)(qi)量嚴(yan)格遵循某種函(han)(han)數(shu)關系，即(ji)怠速(su)控(kong)制閥開度(du)增大(da)，進(jin)氣(qi)(qi)(qi)量相(xiang)應增加。進(jin)氣(qi)(qi)(qi)管路漏氣(qi)(qi)(qi)，進(jin)氣(qi)(qi)(qi)量與怠速(su)控(kong)制閥的(de)開度(du)將不嚴(yan)格遵循原(yuan)函(han)(han)數(shu)關系，即(ji)進(jin)氣(qi)(qi)(qi)量隨(sui)怠速(su)控(kong)制閥的(de)變(bian)化有突變(bian)現象，空(kong)氣(qi)(qi)(qi)流量計因此無法測(ce)出真實的(de)進(jin)氣(qi)(qi)(qi)量，造成ECU對進(jin)氣(qi)(qi)(qi)量控(kong)制不準確，導(dao)致發(fa)動(dong)機怠速(su)不穩。

診斷方法：若聽見進氣(qi)管(guan)有泄漏的“嗤(chi)嗤(chi)”聲，則證(zheng)明進氣(qi)系統漏氣(qi)。故障(zhang)排除：查找泄漏處，重(zhong)新進行(xing)密封(feng)或更(geng)換相關(guan)部件。

配氣相位錯誤故障

配(pei)氣(qi)相位的(de)(de)壓力(li)傳感器(qi)錯誤(wu)會使(shi)氣(qi)門(men)不按規定(ding)時刻開閉(bi)，致使(shi)進(jin)入氣(qi)缸內(nei)的(de)(de)空氣(qi)-量(liang)(liang)減少，同(tong)時由于(yu)竄(cuan)氣(qi)也使(shi)進(jin)氣(qi)管內(nei)的(de)(de)溫度有所升高(gao)，從而(er)使(shi)發(fa)熱元件受到(dao)冷(leng)卻的(de)(de)程(cheng)度降低(di)，因而(er)輸出給E．cu的(de)(de)電壓信號就低(di)，噴油量(liang)(liang)就會減少，容易造成(cheng)發(fa)動(dong)機(ji)在怠速時運轉不穩，出現抖動(dong)。檢查正(zheng)時標記，按照標準重(zhong)新調整配(pei)氣(qi)相位。

噴油器滴漏或堵塞故障

若(ruo)噴(pen)(pen)油(you)(you)(you)器有(you)滴漏或堵塞(sai)(sai)現象，使其無法按(an)照ECU的指(zhi)令進行噴(pen)(pen)油(you)(you)(you)，從而造(zao)成(cheng)混合氣過(guo)濃(nong)或過(guo)稀，使個別氣缸工作(zuo)不(bu)良(liang)，導致壓力(li)傳(chuan)感器發動機怠速不(bu)穩。噴(pen)(pen)油(you)(you)(you)器的堵塞(sai)(sai)引起的混合氣過(guo)稀，還會使氧傳(chuan)感器產生低(di)電位信號(hao)，電腦會根據此(ci)信號(hao)發出加濃(nong)混合氣的指(zhi)令，如果指(zhi)令超(chao)出調(diao)控極限時，電腦會誤(wu)認為氧傳(chuan)感器存在故(gu)障(zhang)(zhang)，并記憶(yi)故(gu)障(zhang)(zhang)代(dai)碼。用聽診器檢查噴(pen)(pen)油(you)(you)(you)器是否發出“咔嘰咔嘰”動作(zuo)聲或測量(liang)(liang)噴(pen)(pen)油(you)(you)(you)器的噴(pen)(pen)油(you)(you)(you)量(liang)(liang)，若(ruo)噴(pen)(pen)油(you)(you)(you)器無動作(zuo)聲或噴(pen)(pen)油(you)(you)(you)量(liang)(liang)超(chao)出標準，噴(pen)(pen)油(you)(you)(you)器即有(you)故(gu)障(zhang)(zhang)予以修復。