论文题目：日产风度A33发动机怠速不稳、加速熄火的诊断与分析

目：日产风度A33发动机怠速不稳、加速熄火的诊断与 论文专业:汽车维修 论文题目:日产风度A33发动机怠速不稳、加速熄火的诊断与分析 申报职称: 师 申报人姓名:本人 申报人单位:XXXXXXXX 注:除论文题目用1号字外～其它均用3号字 should be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wire binding order, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 making cables buried piping application root production, growing where interface is required, only straight pipe, only the wire port connections, welded connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installation, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipment and equipment or piping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of the insulating layer (hot) = shell-wall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, flaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass fiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brushing each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair-faced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able to display strength and aesthetic perception of quality standards. Construction technology requirements are as follows: template template Panel selection and processing require plate high strength, good toughness and 【摘要】 对于电子控制汽油喷射系统，当其发生无故障码的故障现象时可以依据车主提供信息、结构和原理进行故障分析并完成故障排除。介绍了通过检查空气供给系统、点火系统、各传感器工作情况、燃油供给系统，分析故障原因等步骤，排除日产风度A33发动机怠速不稳、加速熄火故障的过程。 现代汽车是一个机电液一体化的产品，往往某一装置或部件发生故障后，如不引起注意并及时排除，就会引起其他系统发生故障，致使汽车不能够正常运转。因此，当某一装置或部件发生故障并排除后，应对其相关部分作相应检查，以保证车辆的正常运转。 掌握汽车结构与工作原理是故障诊断与排除的基础。对于电控汽油喷射系统，经常会出现一些没有故障码提示的话故障或与故障码不符的故障，此时需要根据结构与原理、故障现象对相关部位进行检查，并排除故障;此车为典型的人为故障，首先是火花塞，其次是清洗节气门时将节气门位置传感器的位置调整错误。作为现代修理工，应该认真学习后再来维修车辆，不要盲目地维修不熟悉的车，以免出现意想不到的故障。 关键词:轿车 怠速 诊断 1 故障现象描述 一辆日产风度A33轿车,行驶近10万公里。车主反映此车发动机怠速不稳，加速无力且犯闯，有时加速后还会熄火。 该车的发动机主要技术参数为发动机类型 VQ20DE、发动机形式为横置V型6缸、发动机排量(mL) 1995、最大功率(kW,r,min) 140,6400、最大转矩(N.m,r,main) 179,4000、双顶置凸轮轴(DOHC)、24气门、2.0L汽油机。电控系统为ECCS，采用LH型进气检测方式、多点顺序燃油喷射(MFI)、氧传感器反馈闭环混合气控制、三元催化转换，电子点火(EI)系统、故障诊断采用车载自动诊断系统(OBD)接口、故障诊断采取专用仪器(CONSULT-II)故障读码方式。 2 故障诊断过程 日产风度A33轿车发动机怠速不稳是常见的故障现象，但是加速无力且犯闯，有时加速后还会熄火的故障并不常见。引起发动机怠速不稳的原因很多，主要包括以下主要原因:空气供给系统不畅或堵塞;点火系工作不良;曲轴位置传感器、凸轮轴位置传感器、冷却液温度 st a primer (red paint) and finish. 7.8.2.2 paint appearance color unwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at lea-8.1.8 metal temperature of the insulating layer (hot) = shells. 7.piping and piping, equipment and equipment or piping and other equipment shall have sufficient expansion gap in hot situation7.7.6 cable trays installation, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 ding.aight pipe, only the wire port connections, welded connections are not allowed. 7.7.5 service sleeve should have a good groun>760mm, not >6%. 7.7.4 making cables buried piping application root production, growing where interface is required, only str ameteruld be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diuse of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius shore binding order, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making should be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wiollows: template template Panel selection and processing require plate high strength, good toughness andto display strength and aesthetic perception of quality standards. Construction technology requirements are as ffaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -nt process. 1 fairlacemeeneity of asphalt coating, brushing each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure per show surrounded by glass fiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogld nevshould be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance shouiform, without paint, rust, flaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer 2 传感器、进气温度传感器、氧传感器工作不良;喷油器性能不良或供油压力不正常;电控元件工作不良等。当我们进行维修前，首先要与车主进行沟通，问的内容应当越详细越好，得知此车刚刚做过保养，保养后不久就出现了目前的故障。根据上述原因，遵从由简到繁的顺序，完成故障分析。 具体诊断流程见图1。 有 读取故障码 按故障码提示排除故障 无 是 检查进气系统是否堵塞 清洁 是 否 检查点火系技术状况是否良好 更换相关部件 是 是 检查各传感器性能是否不良 更换相关传感器 是 否 检查喷油器密封及喷射是否良好 更换喷油器 是 是 检查电子控制单元，如有问题更换 更换ECU 否 人为故障，恢复系统 图1 诊断流程 2.1 读取故障码 这一代发动机电控系统的电子控制单元(ECU)采有的是车载自动诊断系统(OBD)接口。接车后，首先连接专用故障诊断仪(CONSULT-II)对发动机电控系统进行检查，但未发现故障码。这时只能按图骥，根据故障现象及工作原理分析故障的原因。 2.2 检查空气供给装置 对所有空气供给装置的真空管、空气软管、空气滤清器及曲轴箱 wall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and p-e insulating layer (hot) = shellquipment or piping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of thand e on, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipmentnections, welded connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installatirt cong cables buried piping application root production, growing where interface is required, only straight pipe, only the wire poameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 makiner ditube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the out r, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe,re binding ordeshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wiel selection and processing require plate high strength, good toughness andgth and aesthetic perception of quality standards. Construction technology requirements are as follows: template template Panto display strenfaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair ushingiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brication. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass ftratiflaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without sipelines should have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, f3 通风装置进行检查，并未发现堵塞及其他异常现象。对怠速控制系统的各个阀进行检查，发现有些脏污，进行清洗后重新装车并调整到正确位置。起动发动机，故障现象依旧。 2.3 检查点火系统 经询问车主，得知此车刚刚做过保养，保养后不久就出现了目前的故障。为此，我们决定对该车进行过的保养项目进行复查。 考虑到该车在更换火花塞时容易出现问题，一旦火花塞换错，就会出现此车发动机表现出的故障，故决定先拆下火花塞进行检查。经检查，发现火花塞虽然是新的，但并不是原车用的，因为原车用的是铂金火花塞，而该车使用的是普通火花塞，而且也不对，看来原因就在于此。在征得车主同意后，我们更换了1组原装的铂金火花塞。 经试车，发动机加速有力，但发动机的怠速依然不稳定。 2.4 检查各传感器工作情况 若曲轴位置传感器、凸轮轴位置传感器、冷却温传感器，进气温度传感器、空气流量计输信号与实际数值有出入时，或氧传感器工作不良时，会造成发动机的怠速依然不稳定。用数字式汽车专用万用表对上述传感器进行检查，其输出信号正常。又用其他车上的相应传感器进行对换实验，故障现象依旧。证明传感器部分没有故障。 2.5 检查燃油供给系统 因怠速不稳，遂怀疑可能是供压力不正常或个别喷油器有故障。拆下燃油分配管的进油管，接上燃油压力表，起动发动机，观察燃油压力表的值数及变化。在怠速时，燃油压力为250kpa，加速时燃油压力略有升高属正常现象。证明燃油压力正常。 将4个喷油嘴拆下在喷油嘴清洗检验仪上进行检查，未发现喷油器有滴漏现象，检查喷雾情况良好，证明喷油器本身没有故障。将喷油器重新装车，起动发动机，故障现象依旧。 2.6 检查电子控制单元 根据上述故障分析判断的过程及结果，认为故障可能在电子控制单元上。这时将另一辆同型号车上的电子控制单元(ECU)拆下换到故障车上，用专用故障诊断仪(CONSULT-II)进行新电子控制单元(ECU)的匹配，启动发动机后，故障现象依旧。 2.7 确定故障原因:人为故障 此时怀疑该车在进行保养时被动过节气门，于是进行检查，发现节气门位置确实人为调整过。正是由于发动机控制单元不能根据节气 -nt process. 1 fairlacemeeneity of asphalt coating, brushing each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure per show surrounded by glass fiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogld nevshould be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance shouiform, without paint, rust, flaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer st a primer (red paint) and finish. 7.8.2.2 paint appearance color unwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at lea-8.1.8 metal temperature of the insulating layer (hot) = shells. 7.piping and piping, equipment and equipment or piping and other equipment shall have sufficient expansion gap in hot situation7.7.6 cable trays installation, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 ding.aight pipe, only the wire port connections, welded connections are not allowed. 7.7.5 service sleeve should have a good groun>760mm, not >6%. 7.7.4 making cables buried piping application root production, growing where interface is required, only str ameteruld be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diuse of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius shore binding order, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making should be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wiollows: template template Panel selection and processing require plate high strength, good toughness andto display strength and aesthetic perception of quality standards. Construction technology requirements are as ffaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able 4 门位置传感器的信号正确的判断发动机的工况，导致发动机的怠速出现异常。在将节气门位置传感器调整到正常位置后，再次起动车辆，发动机加速、怠速均正常，且无加速后熄火现象，故障排除。 3 故障排除 3.1 外观检视 原则上将，节气门位置传感器位置是不允许随便进行调整的，如果调整也要按照维修手册的规定程序进行重新设定。经与车主沟通证实修理人员进行过节气门的清洗，并且发现节气门位置传感器上的螺钉有调整过的痕迹，所以我们必须按照维修手册重新进行设定。 3.2 原理分析 在不正规的调整节气门位置传感器的位置后，节气门位置传感器给电子控制系统(ECU)的信号一直是节气门开启的状态，实际节气门一直是关闭的，电子控制系统为了保证发动机的正常运转，所以系统不停的进行怠速调整，使发动机处于一种不稳定状态。 3.3 消除办法 按照维修手册的程序进行如下操作，连接专用故障诊断仪(CONSULT-II)，点火开关置于“ON”的位置，进入发动机数据流读取模式，启动发动机，至少保持以下操作六秒钟以上，参看下表: 车速 大于4公里每小时 档位 适当的档位(除了P或N档) 经过以上操作后，如图2中所示上方为 节气门位置传感器位置调整示意图，下方为 发动机系统数据流显示状态，将节气门位置 传感器位置调整到节气门开关位置处于关 闭的状态(数据流显示为CLOSED THL/SW ON)是节气门的位置是关闭的;节气门位置 传感器位置调整到节气门开关位置处于开 启的状态(图上为CLOSED THL/SW OFF)时 节气门的位置是打开的;确定以上两种状态 两至三次后，系统数据流所显示的状态正 常。 图2 -each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure placement process. 1 fair ushingiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogeneity of asphalt coating, brication. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance should never show surrounded by glass ftratiflaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer should be tight and without sipelines should have at least a primer (red paint) and finish. 7.8.2.2 paint appearance color uniform, without paint, rust, fwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and p-e insulating layer (hot) = shellquipment or piping and other equipment shall have sufficient expansion gap in hot situations. 7.8.1.8 metal temperature of thand e on, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 piping and piping, equipmentnections, welded connections are not allowed. 7.7.5 service sleeve should have a good grounding. 7.7.6 cable trays installatirt cong cables buried piping application root production, growing where interface is required, only straight pipe, only the wire poameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diameter >760mm, not >6%. 7.7.4 makiner ditube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius should be ? 4 times times the out r, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making use of galvanized steel pipe,re binding ordeshould be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wiel selection and processing require plate high strength, good toughness andgth and aesthetic perception of quality standards. Construction technology requirements are as follows: template template Panto display strenfaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able 5 3.4 原因分析 此车为典型的人为故障，首先是火花塞，其次是清洗节气门时将节气门位置传感器的位置调整错误。作为现代修理工，应该认真学习后再来维修车辆，不要盲目地维修不熟悉的车，以免出现意想不到的故障。 4 结束语 现代汽车是一个机电液一体化的产品，往往某一装置或部件发生故障后，如不引起注意并及时排除，就会引起其他系统发生故障，致使汽车不能够正常运转。因此，当某一装置或部件发生故障并排除后，应对其相关部分作相应检查，以保证车辆的正常运转。 对于人为故障处理起来是比较困难的，需要我们细心认真的观察和与车主的沟通，掌握汽车结构与工作原理是故障诊断与排除的基础。对于电控汽油喷射系统，经常会出现一些没有故障码提示的故障或与故障码不符的故障，此时需要根据结构与原理、故障现象对相关部位进行检查，并排除故障。 参考文献 1 A33车型的维修手册 ollows: template template Panel selection and processing require plate high strength, good toughness andto display strength and aesthetic perception of quality standards. Construction technology requirements are as ffaced concrete is a concrete surface without any decoration, structure appearance quality of concrete structure that is able -nt process. 1 fairlacemeeneity of asphalt coating, brushing each layer thickness in accordance with design requirements. Standard 7.9 7.9 structure per show surrounded by glass fiber cloth uniform, dense, painted pitch inspection should be no delamination, cavitation, homogld nevshould be tight and without stratification. 7.8.2.4 pipelines asphalt, fiber glass fabric corrosion, external appearance shouiform, without paint, rust, flaking, wrinkles, flow marks, scum, paint particles and visible brush marks. 7.8.2.3 interlayer st a primer (red paint) and finish. 7.8.2.2 paint appearance color unwall temperature of environment temperature ? 40 ? c. 7.8.2 paint 7.8.2.l paint of equipment and pipelines should have at lea-8.1.8 metal temperature of the insulating layer (hot) = shells. 7.piping and piping, equipment and equipment or piping and other equipment shall have sufficient expansion gap in hot situation7.7.6 cable trays installation, burrs and dirt and corrosion treatment should be carried out, install the bridge ... 7.8.1.7 ding.aight pipe, only the wire port connections, welded connections are not allowed. 7.7.5 service sleeve should have a good groun>760mm, not >6%. 7.7.4 making cables buried piping application root production, growing where interface is required, only str ameteruld be ? 4 times times the outer diameter of the tube in. 7.7.3 ellipticity of a bent tube, pipe diameter ? 60mm, not >8%, diuse of galvanized steel pipe, tube ends without burrs, smooth. 7.7.2 pipe does not allow bending, bending the bend radius shore binding order, reliable grounding. 7.7 quality standard 7.7.l cables through the cable embedded tube making should be tightened, no loose, Terminal Board wiring should be one on each side, no more than two. J, shielded wire, spare wi6