【正文】 t the engine on the flame after 1min. In the flame flickering lantern engine several times before, restart, engine startup immediately after the flame. Fault reasons: red box SCANNER scanner read fault codes, can also be used to read the manual. Diagnostic connector in the engine firewall, it will be selfdiagnosis input (ST1) and signal back to lose client to interline jumper, connect voltage meter, then the battery anode rod cathode, anode rod from the patient then output (STO), when the ignition switch ON, followed by the number of oscillating voltage meter, you can read the fault code. Clear fault code, then in the ignition switch ON after the fault code when going to shows, crosswiring can be dismantled immediately, car fault code read out for the intake air temperature sensor circuit bad. Troubleshooting: Remove intake air temperature sensor, measuring its resistance, at different temperatures have different resistance. If the resistance of the normal, measuring signal terminal voltage source (that is, on the 25th pin cable), its voltage should be around 5V. In addition, when the ignition switch OFF, the 46 line and the body of mon Ground Ground resistance should be below 5 in Europe. Inspection results, on the 26th line of open circuit, repair the lines, the vehicle returned to normal. Analysis: intake air temperature sensor (ACT) installed in the intake manifold, or installed in the air beside the filter device to detect air entering the cylinder temperature, to amend the fuel injection quantity, so that the air fuel mixing ratio is more suitable in bustion. It uses thermistor sensors for different temperature resistivity changes into voltage signals. The higher the temperature, the lower voltage signal, the less amount of fuel injection. 2, the engine idle speed is too low after warmup, unstable fault detection and diagnosis analysis 1) fault phenomenon Engine Idling after warmup operation, the speed is too low, easy to flame. 2) the cause of the malfunction (1) late ignition timing, (2) Cylinder pression force is too low, (3) poor performance Injector (4) working conditions, bad fuel pump. Control system of the crankshaft position sensor, engine water temperature sensor bad. 3) diagnostic methods (1) check engine light is when the ignition timing, (2) to check whether the plugpass into the trachea, (3) to check whether the gas chamber throttle plug (4) check whether the card throttle resistance, (5) pull down voltage vacuum tube to the regulator to provide vacuum or pressure, check engine idle speed, (6) access to fault codes, the use of the output code (E) of the engine to accelerate the adverse 1, repair examples: Models: Buick CENTURY sedans equipped V6 engine electronic control. Fault phenomenon: moving to accelerate the poor idle when serious jitter, when the intake manifold backfire. Troubleshooting: Replacement of spark plugs and gasoline vapor filter, and clean air filter, fault still. Petrol injection system cleaning agents and special equipment EFI automatic cleaning device cleaning, no effect。 隨著汽車技術(shù)的不斷發(fā)展，對汽車維修人員的要求也越來越高，汽車維修技術(shù)人員只有不斷學(xué)習(xí)現(xiàn) 代汽車技術(shù)相關(guān)知識和理論，更好的掌握汽車電子控制系統(tǒng)的保養(yǎng)，故障判斷及排除方法，學(xué)會使用各種檢測儀器設(shè)備，不斷總結(jié)維修經(jīng)驗，提高維修技術(shù)水平，才能適應(yīng)汽車維修技術(shù)日新月異的發(fā)展。 機械系統(tǒng)：（ 1）汽缸壓力不正常；（ 2）缸墊沖壞；（ 3）空氣 濾清器堵塞，進(jìn)氣管路是否漏氣；（ 4）燃油質(zhì)量不合格。 2）故障原因及檢修 燃油系統(tǒng)：（ 1）燃油管變形；（ 2）檢測燃油泵工作是否正常；（ 3）檢測燃油燃油壓力調(diào)節(jié)器和保持壓力；（ 4）檢查噴油器的噴油量和密封性。 測試燃油壓力，啟動發(fā)動機并改變轉(zhuǎn)速，壓力值在正常范圍內(nèi)。 故障現(xiàn)象：行駛中加速不良，怠速時嚴(yán)重抖動，急加速時進(jìn)氣管回火。 2）故障原因 （ 1）點火正時過遲，（ 2）氣缸壓縮力過低，（ 3）噴油器性能差（ 4）燃油泵工作 狀況不良。 分析：進(jìn)氣溫度傳感器（ ACT）裝在進(jìn)氣歧管上，或裝在空氣器濾芯旁邊，用以檢測進(jìn)入氣缸的空氣溫度，以修正噴油量，使空氣燃油的混合比更適合于燃燒。 故障排除：拆下進(jìn)氣溫度傳感器，測量其電阻，在不同溫度下應(yīng)有不同的阻值。在熄火前發(fā)動機燈會閃爍幾次，重新起動，發(fā)動機起動后馬上熄火。 點火系統(tǒng)：點火正時失準(zhǔn)。最后拆下診斷盒上的短導(dǎo)線即可，該車節(jié)氣門位置傳感器隨著節(jié)氣門轉(zhuǎn)動而改變電位計上可變電阻，控制器則從變化的電壓信號中得知節(jié)氣門的開度與位置。 該車節(jié)氣門位置傳感器為電位計輸出型結(jié)構(gòu)，上有 4 個接線柱，分別為 Vc（電源 腳） IDL（怠速腳）， VTA（輸出腳）和 E2（接地腳）。開啟診斷的塑料蓋，在其背面插座找到 TE1 及 E1 的插孔。 （三）發(fā)動機暖機前怠速不穩(wěn) 維修實例： 車型：豐田皇冠 故障現(xiàn)象 :起動后冷機運轉(zhuǎn)時，怠速運轉(zhuǎn)不穩(wěn)。 2）故障 原因 點火系統(tǒng)：點火正時失準(zhǔn)。 故障原因： （ 1）檢查節(jié)氣門本體的導(dǎo)線線束，觀察膠帶捆綁著的任何部位是否絕緣損壞。 2）故障原因 燃油系統(tǒng)故障： (1)燃油泵工作不正常； (2)噴油器不良； (3)進(jìn)氣管路漏真空；(4)怠速控制閥關(guān)閉不嚴(yán)。 分析燃油管路仍有泄漏處。觀察 10min 后，壓力約為 70KPa，說明系統(tǒng)有泄漏處。 故障現(xiàn)象：發(fā)動機熱車時啟動正常，而冷車時，特別 是早晨第一次啟動時，啟動困難。整個電控系統(tǒng)是以發(fā)動機電子控制器 (簡稱 ECU)為控制核心，以空氣量和發(fā)動機轉(zhuǎn)速計算出基本噴油持續(xù)時間，根據(jù)傳感器檢測與發(fā)動機工況有關(guān)的參數(shù)，對基本噴油持續(xù)時間進(jìn)行修正，以噴油器，點火電子組件和怠速控制閥等為控制對象，保證獲得與發(fā)動機各種工況相匹配的最佳混合氣成分、噴油時刻和點火時刻。電控燃油噴射系統(tǒng)作為汽車的核心組成部分，其性能的好壞直接影響到汽車的動力性、經(jīng)濟性、可靠性、安全性、排放凈化和舒適性。 簽名：