老賓士維修保養-w126、w124、w201: 8月 2013

2013年8月26日星期一

換檔延遲正常嗎?

老賓士722.3/772.4變速箱除了真的不能入檔外，最常被討論的就是變速箱零件老化所以傳輸效能不佳及入檔"D" Or "R"延遲、明顯頓挫感，變速箱大修或是賣車變成車主經常要考慮的必要選項,有沒有可能是其他因素造成的。首先關於入檔"D" Or "R"延遲2秒以內並伴隨頓挫感根據原廠技術手冊是乎是正常的現象，有時候入檔頓挫是因為六腳橡皮老化、真空閥故障或真空管鬆脫、變速箱油規格不合(油溫及油壓不正確)，至於輸出效率不佳可以藉測量儀器來確認，車子雖然老旦不一定不中用，變速箱一但拆開來,裡面的零件就要換新的，廠商給你保固一年。可是有些零件台灣找不到原廠零件需要德定；假如大修後效果不如預期但變速箱又不是壞了....那就鬱卒了。

變速箱零件圖

90-91年賓士車變速箱型號:

變速箱油溫與壓力

入檔延遲與頓挫

賓士W126 W124 M103的引擎檢測數據

老車的引擎數據對於車主來講是很重要的資料,看看哪些是你需要的..

2013年8月25日星期日

BENZ-W1 26 電噴系統故障診斷

賓士汽車的引擎系統可分為電子機械噴射系統和1992 年以後新型的空氣流量式噴射系統兩種。除此之外，美規車系還增加一組方形自我診斷座，用來讀取故障碼。歐規車係就需由圓形測試接頭，模擬自我診斷方式，檢測引擎系統故障。

美規賓士車系CIS-E 引擎故障碼讀取
讀取方式
①點火開關轉至“ ON ”位置但不起動引擎。
②在引擎右側防火牆的方形診斷座上按下2 號位置的按鈕約2-4 秒鐘。
③放開按鈕，同時觀察珍斷座上LED 指示燈，讀取閃動次數所代表的故障碼。
根據資料可查出故障碼的內容如下：

清除方式
①按上文步驟再次讀取故障碼。
②在故障閃動完畢2 秒鐘後，再壓下2 號按鈕持續在6 秒以上。
③當診斷座上的LED 指示燈亮一次後，即表示故障碼已被清除。

歐規BENZ CIS-E 引擎
歐規和美規賓士車均有一個圓形測試接頭，它裝在左前減振器的前方，執行系統診斷時，需使用專業測試表測試其百分比和閉角值。
①靜態測試
等引擎到達工作溫度後，點火開關轉至“ OFF ”，可測試出百分比和閉角值，它所表示的故障內容如下：

②動態測試
起動引擎，並保持在怠速運轉中，此時測出的百分比和閉角所代表的故障如下：

當然不見得所有保修人員都熟悉這樣的檢查流程，但對於引擎問題的診斷至少不至於就瞎子摸象。

2013年8月24日星期六

空氣流量感知器-Air Flow Sensor

怠速不穩、耗油、加速無力，目前台灣已不單獨出售新品(料號3437224035)，原廠新品連同空氣流量感知器一併出售售價約台幣30000元左右；感知器正常使用下約20萬公里電路板感應層將逐漸耗損,導致電壓值不穩進而影響電腦判讀空氣流量數據。

跟據BOSCH產品文件，料件編號:3437224035；F026T03021；3437224015指的是同一個零件；整個零件分為三個機構:

1.防水外殼及橡膠密封條
2.4支固定螺絲(其中2支為訊號調整螺絲，可以改變進氣量的大小)
3.IC電路版(電路板上有一層薄膜，透過與節氣門的指針摩擦產生電位差)

常見的故障大多集中於薄膜磨損，導致訊號無法依節氣門的指針正確的傳導；當訊號不正確ECU就無法計算正確的供油量，引擎就會怠速不穩、耗油、加速無力(前提是點火及氣密條件沒有問題)。大部分的保養廠會調整分油盤供油量來解決車主的問題；比較可行的方式應該是:

1.移動空氣流量感知器測試電壓是否會改變
2.將空氣流量感知器電壓調整至預設值(螺絲須先假固定稍微拴緊來調整)
3.調整分油盤
4.確認引擎工作溫度時怠速轉速(冷車時轉速會比較高)
5.測量CO值(老師傅檢查排氣管用聞的要不惡臭，排氣尾管最好要有水滴)

如果已將上述問題排除(換新料件或是調整至最佳值)，還是無解那就必須檢測其他系統；機械噴射系統的供油及供氣系統不像新型的電腦噴射引擎，全部交由程式來調整，它必須藉由維修人員依手冊及車況來微調，這也是老車好玩的地方。

Testing this component is carried out with ignition on and engine off. The potentiometer is connected by a three pin plug, with locking tags at top and bottom. Ease these out and slightly withdraw the plug, so that the socket pins can be accessed by test leads from your multimeter. The top and bottom pins should have nominally 5 volts across them, as supplied by the computer. The centre pin feeds back to the computer a voltage less than 5 volts for each position of the air flow meter. Connect the multimeter between the centre and the top pin and watch the voltage reading as you very gradually deflect the air flow meter plate. The voltage should increase continually, never dropping out to zero. If it does, you need a new potentiometer. Mercedes only sells these already mounted on a replacement air flow meter and you may think that its cost is comparable to the value of your vehicle. There is information on the web about obtaining a replacement potentiometer at a much lower cost. If you go this way, you'll have to remove the old pot and replace it with a new one, then calibrate it, but that's a simple matter really. One reason for which Mercedes provides an all new solution may be that the sliders that run over the resistance tracks remain in the housing and they may also be worn, so installing a new pot may not produce any improvement. Removing the old potentiometer involves using a very fine screwdriver to insert in the gap between the two roughly circular plastic covers on the front at either end of the potentiometer housing and easing them out, exposing four Torx screws that mount the potentiometer to the air flow sensor body. At this stage it's a really good idea to put a pencil mark around the pot on the air flow sensor body, as an aid in getting the replacement one roughly in the right position. Undo the screws and gently withdraw the pot from its shaft. Look at the tracks and marvel at how the car operated at all! You'll note that the four mounting screws go through slotted holes in the pot housing that allow it to be rotated relative to its operating shaft and this is how the pot is calibrated. Once you have replaced the pot with the screws just loose enough to allow its rotation around the shaft, you reconnect the three pin plug, again with the socket pins exposed for measurement, then measure the voltage at the centre pin. Turn the new pot around the operating shaft until you read about 1 volt. At the 1 volt level the engine will be running rich, but if you try a lower initial setting, you may not be able to start the engine. Now start the engine and get it up to operating temperature, then adjust the pot position until you read 0.7 volts between ground and the centre pin. The pot is now calibrated."