Почему машина глохнет на холостом ходу: Почему глохнет двигатель на холостом ходу

Почему глохнет двигатель автомобиля на холостом ходу

Наверное, каждый автовладелец хоть раз в жизни сталкивался с проблемой глохнущего двигателя, причём это может произойти не только с автомобилями отечественного производства. Так, ещё некоторое время назад большинство водителей сходились во мнении, что чаще всего мотор глох из-за технических особенностей ВАЗ, однако, как оказалось на практике, подобные проблемы довольно часто встречаются и на иномарках. Это значит, что совершенно неважно, отечественный у вас автомобиль или имеет более «благородное» происхождение — он с одинаковой вероятностью может заглохнуть на холостом ходу в самый неподходящий момент.

Главные причины глушения двигателя на холостом ходу

Прежде чем приступить к описанию основных причин, по которым двигатель глохнет на холостом ходу, стоит сказать пару слов о том, как это происходит. Вы садитесь в автомобиль и заводите движок, который функционирует в привычном режиме. Но стоит только убрать ногу с педали газа, как наблюдается падение оборотов, хотя датчик холостого хода показывает номинальные обороты. При этом ясно слышно, что двигатель работает нестабильно, а то и вовсе глохнет. Это проявляется детонацией двигательной установки, что может стать причиной весьма неприятных осложнений.

Необходимо отметить, что при повторном заведении двигателя проблема может не проявиться, и вы с лёгкостью сможете отправиться в дорогу, но через некоторое время глушение мотора вновь повторится. Именно поэтому после обнаружения первых неисправностей стоит немедленно заняться устранением неисправностей.

Практически каждый автовладелец сталкивался с глушением мотора

Однако прежде всего стоит определить, что именно может быть причиной некорректной работы силовой установки. Как правило, автовладельцы и автомеханики сходятся в едином мнении, называя следующие основные причины, почему двигатель может глохнуть на холостом ходу:

• неисправности в работе датчика холостого хода либо его полный выход из строя;
• накопление грязи в дроссельной заслонке;
• выход из строя датчика положения заслонки дросселя;
• загрязнение карбюратора или инжектора (в зависимости от типа автомобиля).

Конечно, в отдельных случаях проблема может иметь более банальный характер: смещение клеммы аккумулятора, пустой топливный бак, использование топлива низкого качества и т. п. Но заострять на них внимание не будем, поскольку решить эти проблемы сможет даже автовладелец-любитель.

Причины неисправности в каждом отдельном случае могут кардинально отличаться, поэтому необходимо быть готовым применять различные меры для их устранения. Как показывает практика, бывалые автовладельцы способны справиться с проблемой самостоятельно, в то время как новичкам лучше сразу обратиться за помощью специалистов.

Есть ли отличия в неровной работе на карбюраторе и инжекторе

Причины глушения карбюраторного и инжекторного двигателя несколько отличаются. Так, для карбюраторных причиной чаще всего служат:

• Выход из строя самого карбюратора по причине замусоривания. Для устранения проблемы необходимо просто промыть и почистить карбюратор.
• Забитый топливный фильтр, а также засорение фильтрующей сетки топливного насоса, которые также необходимо очистить от отработанного топлива и прочей грязи.
• Выход из строя шлангов и различных резиновых соединителей — необходимо просто осуществить их замену.
• Выход из строя электромагнитного клапана — решается путём его замены. Для выявления проблемы необходимо включить зажигание, сбросить с него провод, а спустя несколько секунд снова подключить, при этом должен прозвучать характерный щелчок. Если щелчка не последовало и на панели приборов засветилась контрольная лампа — клапан неисправен.
• Засорение жиклёра холостого хода — решается путём очистки.
• В отдельных случаях проблема может быть связана с некорректной работой датчиков холостого хода, расположения заслонки дросселя, а также коленвала.

Регулятор холостого хода и датчик холостого хода — не одно и то же. В некоторых моделях они могут быть совмещены в один неразборный механизм, в других — по отдельности

Для инжекторных моторов наиболее распространёнными причинами остановки двигателя и падения оборотов считаются:

• Неисправность в работе регулятора холостого хода.
• Недостаточный уровень давления топлива или подсос воздуха — для устранения проблемы необходимо осуществить чистку фильтров, а также убедиться в герметичности соединительных элементов.
• Выход из строя электронных систем автомобиля, для починки которых рекомендуется обращаться в специализированный сервисный центр.
• Проблемы в работе датчика массового расхода воздуха, а также неисправности в системе зажигания — в основном причина связана со свечами зажигания.

Причины остановки прогретого двигателя и на холодную

Специалисты отмечают, что причины остановки двигателя на холодную и горячую в большинстве случаев ничем не отличаются и могут быть вызваны следующими неисправностями:

• утечка вакуума;
• выход из строя крышки распределителя, ротора, проводов зажигания либо свечей;
• некорректно установленный угол опережения зажигания;
• некорректная работа системы ЭБУ (электронного блока управления) автомобиля, выявить которую можно исключительно путём использования специального диагностического устройства;
• неисправность клапана рециркуляции отработанных газов;
• наличие механических повреждений двигателя, а также чрезмерный износ его элементов;
• загрязнение топливных форсунок;
• неисправность регулятора холостого хода (такая проблема часто появляется на «Калинах»).

Причиной остановки мотора на холодную может быть утечка вакуума, загрязнение топливных форсунок, и др

Почему неустойчивы холостые обороты на дизеле и бензине

В большинстве случаев нет никакой разницы в том, бензиновый или дизельный силовой агрегат установлен на вашем автомобиле — причины остановки мотора будут идентичными. В этом случае рекомендуется осмотреть и произвести очистку дроссельных заслонок, а также проверить работоспособность датчиков холостого хода и положения заслонки дросселя. Если проблема не устранена, то, вероятнее всего, придётся осуществлять полную замену вышедшего из строя оборудования, выявить которое можно, обратившись за помощью к специалистам.

Более того, не важно, глохнет двигатель периодически или регулярно — само наличие проблемы свидетельствует о неисправностях, которые необходимо устранить в максимально короткие сроки.

Последовательность диагностики

Никаких точных рекомендаций по последовательности диагностики не способен дать ни один специалист, однако если проблема внезапно глохнущего мотора проявляется периодически, можно немного подождать и постараться определить, при каких обстоятельствах она возникает. Также нелишним будет посещение специализированных форумов, посвящённых проблемам определённой марки и модели автомобиля.

Для проведения максимально точной диагностики рекомендуется подключить автомобиль к специальному диагностирующему прибору, который можно найти на любой специализированной станции техобслуживания.

Что делать, если машина глохнет на ходу? Маленькая хитрость на видео

И помните, что своевременное прохождение ТО и проведение диагностики позволяет заблаговременно выявить и устранить возможные проблемы, а также сохранить ваше время и деньги.

Оцените статью: Поделитесь с друзьями! 90000 Engine Stall Causes and Prevention 90001 90002 When you stall, it usually means you’re procrastinating on doing your homework. When your car stalls, it means the engine has died, which can be a really frustrating and even scary experience. In fact, your car engine can even stop running 90003 90004 while 90005 90006 you’re driving. But do not panic, because we’re here to thoroughly prepare you for a car engine stall in the event it ever happens. 90007 90008 90003 Why is my car stalling? 90006 90011 90002 So what causes car stalling problems? Car engines quit because of a variety if issues around air flow, fuel or mechanics.Some common reasons for motor vehicle stalls include: 90007 90014 90015 An empty gas tank 90016 90015 A fuel mixture that is not rich enough (this is usually the cause of cold stalling and intermittent stalling) 90016 90015 A faulty fuel pump, alternator or EGR valve 90016 90015 A dead battery 90016 90015 A dirty air filter that’s preventing good airflow 90016 90015 Low fuel pressure (if your car only stalls on inclines this may be the case) 90016 90015 Problems with releasing the clutch (manual transmission vehicles only) 90016 90015 Coolant sensor reading hot 90016 90015 Ignition related problems such as loss of spark 90016 90033 90008 90003 90036 90006 90011 90008 90003 Stalling in Manual vs Automatic Transmission Vehicles 90006 90011 90043 Automatics 90044 90002 Automatic vehicles use what’s called a torque converter to manage transmission fluid and keep your engine running while at a stop.If your torque converter fails, the engine can stall out. Torque converters can fail for many reasons, including dirty fluid, overheating and problems with stall speed, which is the RPM at which your torque converter shifts power from the engine to the automatic transmission. In order to check your torque converter, you might have to perform a stall-speed test. Here’s how: 90007 90002 1. First, find out what your car’s RPM 90003 90004 should 90005 90006 be in the car’s manual, then locate your tachometer (a tool that measures RPM).90007 90002 2. Place immobilizers behind your wheels to prevent your car from moving. Crank that parking brake. (Then crank that Soulja Boy.) 90007 90002 3. Press the foot brake all the way to the floor and start your engine. Vroom, vroom. Change gears from park to drive, but instead of hitting the gas pedal, do not take your foot off the brake. We repeat: 90003 do not take your foot off the brake! 90006 90007 90002 4. Keep pressing the brake pedal, but use your other foot to engage the accelerator pedal for a maximum of five seconds.Check your tachometer for the stall speed and see if it reads lower than it should be. When you’re done, be sure to remove your foot from the accelerator pedal first, then the brake pedal. Then you’re safe to crank the parking brake back down. 90007 90002 5. If you need to get a new torque converter, visit an auto shop. Or, if this whole process sounds like something you totally want to avoid, just head to a mechanic and ask them about performing a stall-speed test for you. They can make a recommendation on whether or now you need a new torque converter.90007 90043 Manuals 90044 90002 If you have a 90003 manual transmission 90006, your car is more likely to stall. Why? Because with a stick shift, it’s all about that clutch. If you forget to engage the clutch or switch into the neutral gear when stopping, you can cause the engine to stall. 90007 90008 90003 90071 90006 90011 90008 90003 What Happens When Your Car Stalls? 90006 90011 90002 If the engine quits while you’re driving, the car will first lose power steering and then power brakes.Your first course of action should be to apply the foot brake and steer gradually over to the side of the road. Then, turn on your hazard lights and try to restart your car. If you can not restart it, call an auto mechanic or friend with jumper cables for help. If the jumper cables do not do the trick in rebooting your stalled engine, you may be looking at another problem that requires repair work. 90007 90002 If your engine stalls while your car is at an idle speed (idling means you’re sitting still), you might not be able to steer it to the side of the road.If this happens, turn on your hazard lights and call either the police or roadside assistance to help you safely get your car out of the road. Be sure not to get out of your car and try to push it while you’re in traffic. Your safety should be the number one concern! 90007 90002 If your engine stalls out, use this information so you know what’s happening, and how to handle it. With your newfound knowledge, you’ll be able to diagnose the problem whether you have an automatic or manual transmission, and explain to your mechanic what’s going on.90007 90008 Can natural disasters make my car stall? 90011 90002 We all know that secondhand smoke and smoke from forest fires can wreak havoc on the human body. The effects on a car are also similarly disastrous, though in the case of a vehicle, it requires a large volume of smoke and debris to see negative effects. 90007 90002 90089 90007 90002 People have questioned the effects of smoke on cars and how it could create stalling in the past, but it seems that a surge in debris-filled smoke has caused the car issues to increase.There could be a few different reasons why a vehicle may stall out during a natural disaster, but all of them are indeed smoke-related, mostly in regards to oxygen intake. 90007 90002 The engine of a car can overheat due to smoke’s oxygen suck, leaving its cooling system unable to properly process the engine’s heat. It might not stall immediately, but as the oxygen flowing in decreases, the vehicle may slow down and eventually stop. This process starves your car of fuel, which is what makes it move forward.90007 90002 If you’re trying to drive through a fire, there’s a particularly high chance of a car stalling, with the vehicle’s air filter getting clogged due to ash, smoke, and debris. A clogged air cleaner will reduce the car’s intake of air and reduce the desired effects and operations of the engine. Clogged air filters / cleaners can cause stalling, misfires, loss of power, overheating or engine smoke. 90007 90002 It’s of the utmost importance that you remain safe during a fire. Make sure that you’re evacuating the area quickly, remaining prepared, and observing the effects of a disaster on your car, but more importantly, your health.90007 .90000 Why is Your Car Engine Stop Suddenly? — Vol. 85 | Used Cars for Sale 90001 90002 Posted: 90003 22.Feb 2012 90004 90005 90006 Why is Your Car Engine Stop Suddenly? — Vol.85 90007 90002 Having your engine stop suddenly in not only annoying, it can be downright dangerous! You can easily loose control of your vehicle if your engine cuts out. If you are driving at higher speeds on a highway, this could mean serious trouble. 90005 90002 The most important thing to do if this happens to you is to find out why, so you can get it fixed! With that said, there are numerous reasons why you car engine stop suddenly.90005 90002 Here are a few of them: 90005 90002 90015 90005 90002 90018 Possible damaged O2 sensors 90019 90020 This one falls under the ‘idling’ category. This may be the case if the idle of a cold engine startup is fine but a warm engine idle will surge and then stall. 90005 90002 Eventually most cars will activate your ‘check engine’ light if this is the case. Take a few minutes and let a mechanic check the codes for you, as there are lots of reasons why the light might be on.Any codes that indicate a lean mixture is a solid sign of O2 sensor failure. 90005 90002 These sensors usually last about seventy-five thousand miles. These sensors are not very expensive and you can find them for about fifty dollars and they are easy to replace. This may also be happening because your engine is idling too low or potentially your control module is going, this is also pretty cheap and simple to fix. 90005 90002 90018 Fluid level low on transmission 90019 90020 Have a look the dipstick on the automatic transmission.The owner’s manual will have the correct method for doing this. Normally you should do this with a warm engine if possible. 90005 90002 90018 Plugged catalytic converter 90019 90020 This is an important component of the exhaust system and needs to be kept clear to let the exhaust out. If it gets clogged, the engine has to work harder to idle and accelerate because exhaust is backing up in the pipe. 90005 90002 This can result in no power and stalling. It will also cause crappy fuel economy and weird noises, usually rattling or vibrating in nature.90005 90002 90018 Ignition / computer issue 90019 90020 This could also be an ignition / computer issue where signals are getting crossed and the engine ends up shutting down. When this happens usually all of the ‘engine warning lights’ go on just as the car stalls. 90005 90002 It is especially dangerous because you could be driving along into an intersection and without any warning your car will shut off and you will lose your power steering and brakes. 90005 90002 90018 Overheating 90019 90020 Well your car engine runs on heat.Basically the chemical energy from the fuel is converted into thermal energy as fuel burns. This results in mechanical energy that powers your engine. 90005 90002 Ironically the hotter the engine, the better it runs, problem is if it gets too hot it will start melting the piston heads and that’s not a good thing! 90005 90002 If your engine overheats, it will eventually stop. It may be overheating because your cooling system is malfunctioning, poor airflow throughout radiator, fan clutch slipping, collapsed radiator hose, damaged water pump impeller or a broken radiator cap, to name a few.90005 90002 It’s very important to let your engine cool down and do not try driving it again until you pinpoints the cause. 90005 90002 90018 Engine Bolts Loose 90019 90020 This one does not happen very often but it definitely has happened, particularly with the Golf Volkswagen Golf Diesel. If you’ve had some maintenance on the engine, particularly a timing belt change, be sure the bolts on the bottom of the engine have been secured properly. 90005 90002 If these bolts are not tightened, the natural running of the engine will cause the bolts to loosen further and eventually the timing will be thrown off with the mechanics of your engine and the engine will self-destruct.90005 90002 Your car will get really loud and you will hear a hammering sound. If you keep going the motor will literally fall out and of course quit running while you are driving. 90005 90002 This may seem a little extreme and it is but unfortunately I can vouch for this one first hand! 90005 .90000 Why Does my Automatic Car Stall 90001 90002 90003 Automatic cars have been a boon to the motor world. They have made driving easier for everyone out there. They are easy to run and operate, but because they are quite new in the market, not much information is available for their issues. You must be aware of some reasons why a manual transmission car stalls, but what if you are running an automatic car? Having your car stalled in the middle of a red light or speed breaker can be an embarrassing situation for sure.If you are still thinking about 90004 why your automatic car stalls 90005, this 90004 oneHOWTO 90005 article is going to give you detailed information on the rest of the symptoms you’ll notice depending on the source of the problem, so that you can get it fixed accordingly. 90008 90009 Problem with the torque converter 90010 90003 An automatic car has a torque converter which serves as a replacement for the mechanical clutch of a manual transmission car. The purpose of a torque converter is to unlock while accelerating or decelerating.Sometimes, braking takes place even 90012 before the torque converter is asked to 90013 do it, due to which the engine loses power and stalls. 90008 90015 Signs of a bad torque converter 90016 90017 90018 Check your temperature gauge as your car may also be overheating 90019 90018 It starts to stall when you accelerate over 30 MPH 90019 90018 Clicking noise 90019 90024 90015 What to do? 90016 90003 If you have determined that this is the problem, it’s best you take it to a trusted mechanic as soon as possible so he / she can fix the problem.90008 90009 Dirty air flow sensor 90010 90003 A dirty or malfunctioning air flow sensor can be responsible for the stalling of your automatic car. An automatic car has several sensors that are responsible for sending relevant information to the vehicle’s computer system. The air flow sensor is designed to monitor the quantity and quality of air entering the car’s engine. With this information, the engine is able to determine how much fuel should be used. If your car’s sensor has become dirty or faulty, then it will give incorrect information to the car’s engine, thus causing the car to stall while idling.90008 90015 How to know if you have a dirty air flow sensor 90016 90017 90018 Car stalls when idling 90019 90018 The engine light may be on 90019 90018 Check your car’s computer through a mechanic’s digital car diagnosis scanner 90019 90024 90015 What to do? 90016 90003 If that’s the reason for your car stalling, it is better to get it cleaned, fixed or replaced as soon as possible. 90008 90009 Issue with the idle circuit 90010 90003 An automatic car has an idle circuit that is used to control air that circulates during idling.If the idle circuit stops working properly, then the car will not receive the right amount of oxygen required for operation. In that case, the car stalls due to non-combustion of the fuel. 90008 90015 How to know if there’s a problem with the idling circuit 90016 90017 90018 Your engine will run roughly 90019 90018 Your car does not stall at a high speed 90019 90024 90015 What to do? 90016 90003 As there are different causes for this, you should further asses the idle circuit to find the source of the problem.90008 90009 Clogged air control valve 90010 90003 The air control valve in your automatic car is responsible for allowing just the right amount of air to enter into your car’s engine. In other words, it works as an air regulator to help the engine keep running properly. But sometimes, carbon may build up on this air control valve, due to which it stops working properly and sends incorrect amount of air into your car’s engine. 90008 90015 How to know if the air control valve is clogged 90016 90003 If this happens, your car will start stalling at red lights and speed breakers.90008 90015 How to fix it 90016 90003 You can clean or replace it to let it work as required. 90008 90075 90009 Malfunctioning oxygen sensor 90010 90003 Automatic cars have an oxygen sensor that monitors the oxygen level of the air being pushed out. Sometimes, this sensor does not work properly and the car stalls because it can not understand that there is a 90012 lack of oxygen required 90013 for combustion. 90008 90015 How to know if your oxygen sensor is malfunctioning 90016 90017 90018 Your engine light will come on 90019 90018 Your car’s mileage will be significantly reduced 90019 90018 Your engine may misfire 90019 90024 90015 How to fix it 90016 90003 In this case, you should replace the sensor or take it to a professional so he or she can do so.90008 90009 Stale fuel 90010 90003 If the fuel inside your car has gone stale, or if it has higher ratio of water inside it, then it becomes more difficult for the car’s engine to achieve combustion. Sometimes, the octane rating of your car’s fuel also plays a role in 90004 causing your automatic car to stall 90005. The octane level in your car’s fuel is responsible for determining how hot it will burn. 90008 90015 How to know if fuel is stale 90016 90017 90018 Your octane level will not be hot enough.90019 90018 Your engine will not run as well as it used to and may not start 90019 90024 90015 How to fix it 90016 90003 Use an ethanol stabilizer, though it is best if you let a professional do so. 90008 90009 Worn out spark plugs 90010 90003 Automatic cars have spark plugs to send electric currents to the engine. If your plugs have worn out, the flow of electric current will get disrupted and your car will misfire or stall during operation. 90008 90015 How to know if your spark plugs are worn 90016 90017 90018 Your car will overheat 90019 90018 You will notice oil seeping in the spark plugs 90019 90018 Your injectors will be dirty 90019 90024 90015 How to fix it 90016 90003 If this is the reason for your automatic car stalling, then it is advised to get them replaced immediately.90008 90132 90003 If you want to read similar articles to 90012 Why Does my Automatic Car Stall 90013, we recommend you visit our Car Maintenance and Repair category. 90008 .90000 Why Does My Engine Start But Then Stop? 90001 90002 90003 Checking the IAC (for Engines With Multiport Injection Systems, Most Modern Engines): 90004 90005 90002 In most cases, the problem here is associated with the idle air control (IAC) valve. 90007 The IAC valve is controlled by the computer and allow airs to bypass the throttle valve under idle or cold temperature conditions to prevent a rough idle or keep the engine from stalling. You can test the IAC valve using a digital multimeter: 90005 90009 90010 First, unplug the IAC electrical connector.90011 90010 Turn the ignition key to the On (run) position but do not start the engine. 90011 90010 Set your voltmeter to 20 Volts range (or above 15 Volts) on the DC (direct current) scale. 90011 90010 Connect your black meter lead to ground (engine metal surface or battery negative post, for example) and with the red meter lead probe the terminals on the harness side. 90011 90010 You should get around 10 to 12 volts, approximately, from one of the terminals. This is the incoming signal from the engine control module (car computer).If not, there are problems in that side of the circuit. 90011 90020 90002 Now measure the condition of the valve by measuring resistance across the IAC connector terminals. 90005 90009 90010 Set your voltmeter to ohms for this measurement. 90011 90010 You should get anywhere from 6 to 13 ohms of resistance. 90011 90020 90002 90003 To check for a possible internal short: 90004 90005 90009 90010 Check for resistance from each IAC connector terminal and the IAC valve body with your voltmeter.90011 90010 You should get around 10,000 ohms of resistance. 90011 90020 90002 90003 Checking the internal physical condition of the IAC valve: 90004 90005 90002 A blocked IAC may cause the engine to die as soon as it starts if the valve sticks close. IAC valves may fill with carbon deposits overtime, preventing the pintle from moving, or blocking valve passages. 90005 90002 On most vehicle models, the IAC valve is readily accessible and can be removed easily by unscrewing a couple of mounting bolts.90005 90009 90010 First, turn the ignition key off and remove the key. 90011 90010 Unplug the IAC valve electrical connector. 90011 90010 Unscrew the valve mounting bolts and remove the valve from the vehicle. 90011 90010 Check the valve’s pintle and housing for carbon buildup. If necessary, clean the valve with carburetor cleaner and a soft rag to remove deposits. 90011 90010 Also, check the valve O-ring. It should be soft and in good condition. Otherwise, replace it. 90011 90020 90002 Consult your vehicle repair manual for the recommended testing procedures for your particular vehicle model, if necessary.90005 90002 Your particular fuel injection system may have other necessary adjustments. For example, you may need to adjust 90005 90063 90010 the idle speed 90011 90010 the throttle cable 90011 90010 the throttle plate stop 90011 90010 the idle air-fuel mixture 90011 90072 90002 Consult your vehicle repair manual, if necessary. 90005 90002 90003 Troubleshooting the ECT (Engine Coolant Temperature) Sensor 90004 90005 90002 The ECT measures engine operating temperature and sends this information as electrical data to the computer.The car computer uses this information, and information from other sensors, to adjust ignition timing for better engine efficiency. 90005 90002 Thus, a bad ECT sensor can have a direct impact on engine performance. If the sensor causes a lean air-fuel mixture the engine may idle rough or stall. 90005 90002 Most ECT sensors use a thermistor to vary the voltage signal sent to the computer according to engine coolant temperature. The higher the coolant temperature, the lower the sensor resistance and higher the signal voltage.90005 90002 To test the ECT sensor: 90005 90009 90010 Locate the sensor. It’s usually close to the thermostat housing. 90011 90010 With the engine turned off and cool, unplug the ECT sensor electrical connector. 90011 90010 Set your digital multimeter (DMM) to the ohms scale and measure resistance across the sensor terminal. Make a note of the resistance value. 90011 90010 Plug in the sensor electrical connector and start the engine. Let the engine idle for about 15 or 20 minutes so that it reaches operating temperature.90011 90010 Shut off the engine. 90011 90010 Unplug the ECT electrical connector and measure resistance across the sensor terminals as you did in step 3. 90011 90010 This time, sensor resistance should be considerably lower. For example, depending on your particular sensor configuration and engine model, the sensor may have 40K ohms when the engine is cold but 2K ohms when hot. 90011 90010 Compare your results to the specifications listed in your vehicle repair manual. 90011 90020 90002 A failing ECT sensor can trigger the check engine light.If your sensor checks Okay during your tests, but the computer says there’s a problem with it, check the sensors circuit between the ECT and the computer for bad connections or damaged wire. 90005 90002 Also, check that the computer is sending the correct reference voltage to the sensor. 90005 90063 90010 Unplug the ECT sensor electrical connector. 90011 90010 Turn the ignition key to the On position, but do not start the engine. 90011 90010 Measure the voltage at the harness connector (the one leading to the computer) with your voltmeter.90011 90010 Usually, you should read about 5 volts at the connector. If not, there’s a problem in the circuit. 90011 90072 90002 90003 Checking for a Stuck EGR Valve 90004 90005 90002 The exhaust gas recirculation (EGR) systems reintroduces exhaust gases into the combustion chambers to reduce engine temperature and poisonous emissions. 90005 90002 It is common for the EGR valve passages to get blocked from carbon buildup. Carbon deposits may prevent the valve from closing, causing the engine to stall at idle.Also, an EGR valve may leak through the base, causing the engine to stall at idle, at deceleration, or during a quick stop. 90005 90002 If you’ve never checked under the valve, or it’s been a few years since you last checked, it might be a good idea to take a look now. But make sure to have on hand a gasket replacement. You may need to install a new one. If you can not find one for your particular vehicle model, you still can buy gasket paper at your local auto parts store and make the gasket yourself.90005 90063 90010 Most EGR valves are accessible and not difficult to remove. Check the EGR valve configuration for your particular model, though, to make sure you have all the tools necessary for the job. Usually, all you need is a couple of wrenches, a ratchet, the appropriate socket sizes and, sometimes, a pipe wrench to disconnect the valve from the exhaust pipe. Consult your vehicle repair manual, if necessary. 90011 90010 Remove carbon deposits from under the valve and intake ports using carburetor cleaner.Make sure not to allow carburetor cleaner to reach the valve diaphragm or any electrical circuits, depending on your particular model, or you may ruin the valve. 90011 90010 Reinstall the valve using a new gasket, if necessary. 90011 90072 90002 90003 Checking the EGR Valve: 90004 90005 90002 Depending on your particular EGR valve configuration, you probably can stick your finger through the underside of the valve and try to move the internal diaphragm. If the diaphragm does not move, it may be stuck.90005 90002 Here are a couple of alternative methods to check for diaphragm movement: 90005 90063 90010 Operate the accelerator linkage with your hand to increase engine speed. You may be able to see the diaphragm moving using a mirror placed under the EGR valve. If you can see the diaphragm with the mirror, but you can not see it moving as you operate the accelerator linkage, the diaphragm might be stuck. 90011 90010 You can also use a hand-held vacuum pump. You can do this test with the engine off and using a mirror to watch diaphragm movement.Disconnect the vacuum hose form the valve and connect the vacuum pump instead. Apply about 15 in-Hg of vacuum to the EGR valve while watching for diaphragm movement with the mirror. If the diaphragm does not move, it might be stuck. 90011 90072 90002 Another cause for the valve diaphragm to fail is wear or damage that causes it to leak exhaust gases. A quick way to test for a leaking diaphragm is using carburetor cleaner. 90005 90063 90010 Block the wheels using wooden blocks. 90011 90010 Set your transmission to Park (automatic) or Neutral (standard).90011 90010 Start the engine and pop the hood open. 90011 90010 Spray a quick burst of carburetor cleaner under the valve, towards the diaphragm. 90011 90010 If the engine RPMs increase when you spray, the diaphragm is leaking and you need to replace the valve. 90011 90072 90002 90003 Bad Catalytic Converter 90004 90005 90002 A bad catalytic converter can also cause you problems at idle. Depending on the particular problem, it may show other symptoms as well: 90005 90063 90010 a smell of rotten eggs 90011 90010 rattling sounds 90011 90010 poor engine power 90011 90072 90002 One of the most common problems with a catalytic converter is a plugged unit.The internal substrate becomes partially restricted or disintegrates. 90005 90002 Usually, problems with the catalytic converter trigger the check engine light (CEL). The computer may store a P0420 through P0423 code. If you find a catalytic-converter-related code, do troubleshoot the catalytic converter before replacing it, to confirm that the cat is in fact bad. Catalytic converters are expensive and you need to make sure that some other components is not involved in the problem. If necessary, consult your vehicle repair manual.90005 90002 90003 Checking the IAC on Vehicle Models With Throttle Body Injection (TBI) Systems: 90004 90005 90002 Many vehicles equipped with TBI systems also have an IAC valve controlled by the computer. 90005 90063 90010 You can use the test described in the previous section, if your vehicle has an IAC valve. 90011 90010 Besides, some of these systems may have an idle speed adjustment (consult your repair manual), 90011 90072 90002 Usually, you can adjust idle speed by hooking up a tachometer (some digital multimeters have this feature) to the engine.Then, you can turn the idle speed screw on the throttle body or carburetor until the RPMs are set according to specifications. 90005.