Fuel supply system malfunction

進(jìn)氣管出現(xiàn)回火是由燃油供應(yīng)不足，混合氣過(guò)稀引起。混合氣過(guò)稀使混合氣燃燒速度減慢，燃燒一直延續(xù)排氣行程終了進(jìn)氣門(mén)開(kāi)啟的時(shí)候，新鮮混合氣遇到氣缸內(nèi)未排凈的燃燒氣體而被點(diǎn)燃，并逆流經(jīng)進(jìn)氣歧管從進(jìn)氣口噴出而回火。

The occurrence of backfire in the intake pipe is caused by insufficient fuel supply and a lean mixture. The mixture is too lean, which slows down the combustion speed of the mixture. The combustion continues until the exhaust stroke ends. When the intake valve opens, the fresh mixture encounters the combustion gas that has not been completely discharged from the cylinder and is ignited. It then sprays out from the intake port through the intake manifold and backfires.

點(diǎn)火系故障

Ignition system malfunction

進(jìn)氣管出現(xiàn)回火是因?yàn)辄c(diǎn)火過(guò)晚或火花質(zhì)量差。一方面使開(kāi)始燃燒的時(shí)刻推遲；

The occurrence of backfire in the intake pipe is due to late ignition or poor spark quality. On the one hand, it delays the start of combustion;

另一方面也會(huì)使燃燒速度減慢，從而導(dǎo)致燃燒一直延續(xù)到進(jìn)氣門(mén)開(kāi)啟，引起進(jìn)氣管回火。同時(shí)伴隨的現(xiàn)象還應(yīng)有：發(fā)動(dòng)機(jī)加速時(shí)轉(zhuǎn)速提高緩慢，急加速時(shí)回火現(xiàn)象明顯，有時(shí)緩加速時(shí)也有回火現(xiàn)象，同時(shí)排氣管排氣聲發(fā)悶，發(fā)動(dòng)機(jī)溫度易升高。

On the other hand, it can also slow down the combustion speed, leading to combustion continuing until the intake valve opens, causing the intake pipe to backfire. At the same time, accompanying phenomena should also include: slow increase in engine speed during acceleration, obvious backfire phenomenon during rapid acceleration, and sometimes backfire phenomenon during slow acceleration. At the same time, the exhaust sound from the exhaust pipe is muffled, and the engine temperature is prone to rise.

如果在進(jìn)氣管回火的同時(shí)，機(jī)體抖動(dòng)嚴(yán)重，排氣管放炮，發(fā)動(dòng)機(jī)功率嚴(yán)重下降，則多是由點(diǎn)火錯(cuò)亂而引起的。由于點(diǎn)火錯(cuò)亂，當(dāng)某缸處于進(jìn)氣行程進(jìn)氣門(mén)開(kāi)啟，恰好該缸火花塞點(diǎn)火，則會(huì)形成進(jìn)氣管回火。

If the engine shakes severely, the exhaust pipe bursts, and the engine power drops significantly while the intake pipe backfires, it is mostly caused by ignition misalignment. Due to ignition misalignment, when a certain cylinder is on the intake stroke and the intake valve opens, and the spark plug of that cylinder ignites, it will form a backfire in the intake pipe.

如果檢查確認(rèn)各缸分高壓線沒(méi)有插錯(cuò)，則多為分電器蓋擊穿。需要引起注意的是分電器蓋存在輕微擊穿時(shí)，一般情況下發(fā)動(dòng)機(jī)在無(wú)負(fù)荷空轉(zhuǎn)時(shí)工作正常，但在熱車(chē)重負(fù)載爬坡時(shí)有回火現(xiàn)象，且回火時(shí)動(dòng)力明顯下降。

If it is confirmed that the high-voltage lines of each cylinder are not inserted incorrectly, it is mostly due to the breakdown of the distributor cover. It should be noted that when there is a slight breakdown in the distributor cover, the engine generally works normally when idling without load. However, there is a phenomenon of backfire when climbing a hot vehicle with heavy loads, and the power significantly decreases during the backfire.

如果發(fā)動(dòng)機(jī)空轉(zhuǎn)時(shí)工作正常，急加速或急減速時(shí)有時(shí)回火；高速行駛時(shí)有不規(guī)則的回火現(xiàn)象；在不平道路上行駛時(shí)回火頻繁，對(duì)于傳統(tǒng)有觸點(diǎn)點(diǎn)火系來(lái)說(shuō)多因分電器搭鐵不良，對(duì)電子點(diǎn)火系來(lái)說(shuō)可能是點(diǎn)火器等搭鐵不良或點(diǎn)火系某傳感器松動(dòng)等。搭鐵不良的分電器或點(diǎn)火器當(dāng)發(fā)動(dòng)機(jī)振動(dòng)較大使分電器搭鐵時(shí)，相當(dāng)于低壓回路斷開(kāi)，產(chǎn)生高壓電。若分火頭正好指向某個(gè)處于進(jìn)氣行程的氣缸，則會(huì)引起進(jìn)氣管回火。

If the engine operates normally while idling, and sometimes backfires during sudden acceleration or deceleration; Irregular tempering phenomenon during high-speed driving; When driving on uneven roads, frequent backfire may occur. For traditional ignition systems with contact points, it is often due to poor grounding of the power distributor. For electronic ignition systems, it may be due to poor grounding of the igniter or a loose sensor in the ignition system. A poorly grounded distributor or igniter. When the engine vibrates heavily and the distributor is grounded, it is equivalent to a disconnection of the low-voltage circuit, generating high-voltage electricity. If the ignition head points directly at a cylinder in the intake stroke, it will cause the intake pipe to backfire.

對(duì)于無(wú)分電器雙缸同時(shí)點(diǎn)火的點(diǎn)火系來(lái)說(shuō)，急加速時(shí)出現(xiàn)回火現(xiàn)象還有一個(gè)常見(jiàn)的故障原因，那就是火花塞不良。在

For ignition systems with dual cylinder ignition without a distributor, a common cause of backfire during rapid acceleration is poor spark plug. stay

檢查高壓線無(wú)漏電、斷路后，試換火花塞不失為上策。

After checking that there is no leakage or open circuit in the high-voltage line, it is still best to replace the spark plug.

機(jī)械故障。

Mechanical failure.

如果發(fā)動(dòng)機(jī)低速運(yùn)轉(zhuǎn)時(shí)進(jìn)氣管回火。排氣管有“突突”聲，轉(zhuǎn)速提高后癥狀減輕，則應(yīng)檢查某氣缸壓縮壓力比正常值是否低0．2MPa以上。若將此缸斷火，回火現(xiàn)象消失，則說(shuō)明該缸進(jìn)氣門(mén)密封不嚴(yán)。電于進(jìn)氣密封不嚴(yán)，該缸作功時(shí)，燃燒的高溫氣體便會(huì)通過(guò)進(jìn)氣門(mén)進(jìn)入進(jìn)氣歧管，引起進(jìn)氣管回火。因?yàn)榘l(fā)動(dòng)機(jī)轉(zhuǎn)速提高后，氣門(mén)的相對(duì)漏氣率降低，因此回火現(xiàn)象在低速時(shí)明顯，高速時(shí)減輕。

If the intake pipe backfires when the engine is running at low speed. If there is a "popping" sound in the exhaust pipe and the symptoms alleviate after the speed is increased, it is necessary to check whether the compression pressure of a certain cylinder is lower than the normal value by more than 0.2MPa. If the cylinder is turned off and the tempering phenomenon disappears, it indicates that the intake valve seal of the cylinder is not tight. When the intake seal of the electric cylinder is not tight, the high-temperature combustion gas will enter the intake manifold through the intake valve when the cylinder is working, causing the intake pipe to backfire. Because the relative leakage rate of the valves decreases as the engine speed increases, the phenomenon of backfire is more pronounced at low speeds and less pronounced at high speeds.

如果發(fā)動(dòng)機(jī)工作時(shí)，連續(xù)有節(jié)奏地出現(xiàn)回火，同時(shí)動(dòng)力下降某缸斷火后，回火現(xiàn)象消失，則多是因?yàn)樵摳着艢忾T(mén)調(diào)整螺栓松脫或推桿折斷，使該排氣門(mén)無(wú)法開(kāi)啟或開(kāi)度過(guò)小。由于排氣門(mén)不能完全開(kāi)啟，使得該缸廢氣不能及時(shí)完全排出，在進(jìn)氣門(mén)開(kāi)啟時(shí)，尚未排出的高溫廢氣便進(jìn)入進(jìn)氣歧管，引起進(jìn)氣管回火。可用斷缸法找出故障缸，然后打開(kāi)氣門(mén)室蓋，檢查該缸排氣門(mén)螺栓及推桿是否異常。

If the engine experiences a continuous and rhythmic flashback while working, and the flashback disappears after a certain cylinder is shut off due to a decrease in power, it is mostly because the exhaust valve adjustment bolt of the cylinder is loose or the push rod is broken, making the exhaust valve unable to open or opening too small. Due to the incomplete opening of the exhaust valve, the exhaust gas in the cylinder cannot be completely discharged in a timely manner. When the intake valve is opened, the high-temperature exhaust gas that has not yet been discharged enters the intake manifold, causing the intake pipe to backfire. The cylinder failure method can be used to identify the faulty cylinder, then open the valve cover and check if the exhaust valve bolts and push rods of the cylinder are abnormal.

如果發(fā)動(dòng)機(jī)工作時(shí)，進(jìn)氣管連續(xù)回火，低速時(shí)更明顯，相鄰的兩缸中某缸斷火。回火現(xiàn)象消失。則可能是因?yàn)橄噜弮筛字g的氣缸墊燒穿。因?yàn)橄噜弮筛字g的氣缸墊燒穿，使某缸做功時(shí)，燃燒著的混合氣進(jìn)入相鄰氣缸，若此時(shí)這個(gè)缸的進(jìn)氣門(mén)處于開(kāi)啟狀態(tài)，則會(huì)形成進(jìn)氣管回火。可用斷缸法找出工作不良的兩個(gè)氣缸，檢查兩缸的配氣機(jī)構(gòu)，如電控失調(diào)或元件及線路有故障，也會(huì)導(dǎo)致混合氣過(guò)稀，進(jìn)氣管回火放炮。

If the intake pipe continuously backfires while the engine is operating, it is more pronounced at low speeds, and one of the adjacent cylinders misfires. The phenomenon of tempering disappears. It may be because the cylinder gasket between adjacent cylinders is burned through. Because the cylinder gasket between adjacent cylinders burns through, when a certain cylinder does work, the burning mixture enters the adjacent cylinder. If the intake valve of this cylinder is in an open state at this time, it will form a backfire in the intake pipe. The cylinder cut-off method can be used to identify the two cylinders that are not working properly, and to check the valve distribution mechanism of both cylinders. If the electronic control is out of control or there are faults in the components and circuits, it can also cause the mixture to be too thin, and the intake pipe to backfire and explode.