Car stutters when idling

My car will 'stutter' when shifting, or when slightly 'below' the speed when in specific gears (i.e., when in third, if the car is going <30, the car stutters). Sometimes, specifically in second gear, the car will not 'accelerate' appropriately–the car is making all the right sounds for accelerating, but the car doesn't 'go' any faster. Also, in those instances, the car check engine light will flash, come on, and I must stop the car entirely. once i stop and restart, everything is semi-normal–all acceleration in each gear is stuttering after that howeve
Experienced mechanics share their insights in answering this question :
Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air-flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. Due to the number of different things that may cause an engine misfire, the quickest and easiest way to diagnose this type of problem is to hook the vehicle up to a scanning tool which will download any potential fault codes that may have registered in the vehicle’s computer as a result of the poor running condition. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

How to Identify and Fix Common car Problems ?

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Common reasons for this to happen:

Old and worn spark plugs and wires (most commonly the issue) Loose or disconnected hoses on and around the engine (not the coolant hoses that go to and from the radiator) are frequently culprits behind intermittent engine operation.

Along with faulty spark plugs, a build-up of dirt and grime is the likely cause of cars stuttering when idle. A clogged filter or fuel injection system can starve your engine of fuel or oxygen, causing your car to judder and shake.
Common reasons for this to happen:

Faulty spark plugs or wires. Faulty ignition coil. Broken piston rings.

So, if your car starts stuttering, there`s a good chance there`s an issue with your spark plugs (or the cables attached to them). It`s not unusual for these car parts to wear out, and a faulty spark plug will cause your engine to misfire and jerk when you accelerate and for your engine to be much louder than usual.
An indication that a vehicle is not receiving the right mixture of air and fuel is if the vehicle jerks or surges forward at high speed. Several components of the fuel or air intake system could cause this jerking or surging sensation to happen. Issues within these systems can also cause fuel economy to worsen.
Dirty or Worn-Out Spark Plugs

Often, your car shakes when idle simply because it`s time to replace your spark plugs! When yours are dirty or worn out, they fail to fire in the right way. If this happens, they`re unable to ignite the fuel located within each of the piston cylinders on time.

How to fix it? Cleaning or replacing the fuel filter and adding a fuel injector cleaning treatment to the fuel tank should take care of clogged fuel injectors. If the rough idle persists, it`s time to take your car to an auto repair shop.
While it may seem like a small problem on its own, rough idling is a sign that some part of your engine isn`t working properly. Over time, rough idling can result in poor gas mileage, starting issues and major engine problems.
The most common causes of misfires are worn, improperly installed, and mishandled spark plugs, malfunctioning ignition coils, carbon tracking, faulty spark plug wires and vacuum leaks.
What Does Code P0301 Mean? P0301 definition: Cylinder 1 misfire detected. Diagnosis: A misfire can be caused by anything from faulty spark plugs to low engine compression.
Hi there – if your car stutter-starts, but runs fine once it is running, you probably have a problem with the fuel system check valve. This valve maintains some fuel pressure in the system so that your car starts faster once the key is turned to “Start”.
When you`re in motion at low revs your car judders, until you accelerate up to a higher speed and move into higher gears. What might be causing this? Worn engine mounts. Loose or worn engine mounts, which hold the engine to the chassis, could be the culprit.
An engine that is hesitating to accelerate is most likely dealing with a fuel/air mixture that is too lean. Engine`s that are running inefficiently will begin to show signs like hesitation which will only become worse over time.
When the transmission jerks between gears or the transmission is shifting hard, it should be taken as a warning that your transmission needs repair. When a transmission is shifting hard or slipping it`s time for an inspection.
A Transmission Fault

Shifting issues can sometimes cause your vehicle to feel like it is jerking when accelerating. If you have internal transmission damage, it can cause the gears to slip [and] engage over and over again, which feels like jerking when accelerating.

Improperly functioning spark plugs cause an uneven burn of fuel in the engine, resulting in fluctuating RPMs and a louder noise. You might also experience increased vibrations of your vehicle while sitting idle or while traveling at low speeds. These vibrations originate from the engine and can shake the entire car.
The short answer is no. There is no known cure for stuttering, and like any other speech disorder, it requires therapy and practice to treat or manage it, and while some people report that their stutter suddenly “disappears”, for most adults who stutter they will continue to do so for their entire lives.
If the fuel amount is too much or too little, the engine may begin to sputter. Your mass airflow sensor tells you how much air is in the engine. Just like the oxygen sensor, the engine will sputter if there is too much or too little air. Spark plugs are an integral part of your engine.
Dirty fuel injectors may cause your vehicle`s engine to misfire. This problem makes the motor feel as though it is sputtering — sending vibrations through the car. Such misfires can happen when a fuel injector problem mixes up the delicate balance between fuel and air entering the engine.
A clogged or failed exhaust gas recirculation or crankcase ventilation valve or faulty oxygen sensor can send the wrong signals to the computer and cause misfires.
A misfire feels like your engine suddenly loses power. You might experience a hesitation when you try to accelerate the vehicle. If it feels like your vehicle is accelerating slower than usual or if it feels rough, the cause could be an engine misfire.
The damage you see will help you determine the cause of the misfire. If the spark plug is just old, replacing it may solve the problem. Make sure to replace and properly gap new spark plugs. A spark plug that looks black or carbon fouled at the end means the engine was running rich (too much fuel).
What does the P0300 OBD-II code mean? When a P0300 trouble code is triggered, it indicates that misfiring occurs in random or multiple cylinders. This happens when there is a deficient amount of fuel being burned within a cylinder.
Engine Running Rough and Rough Idle

Another common symptom of the P0301 fault code is the engine running rough. Because there`s a misfire in engine cylinder 1, it`s more than likely that your car`s engine won`t work properly. You`ll notice it sounds different. Almost as if it is out of tune.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car has a rough idle when I start my car, when I stop at a light my car turns off. Is it the purge sensor?
ANSWER : This may be a result of a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

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Car stutters when idling
ANSWER : Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air-flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. Due to the number of different things that may cause an engine misfire, the quickest and easiest way to diagnose this type of problem is to hook the vehicle up to a scanning tool which will download any potential fault codes that may have registered in the vehicle’s computer as a result of the poor running condition. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

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My car stutters after driving it for a few minutes – 2002 Toyota
ANSWER : This may also be caused by what is called the fuel pressure regulator. This is a unit that helps to maintain the fuel pressure at the proper level. When this is not working properly, the fuel pump may be pumping properly, but the fuel may not arrive at the fuel injectors at the proper psi. When this happens, this can cause a lean fuel condition which may cause the car to hesitate, misfire or stall. I would recommend having an expert from YourMechanic come to your location to diagnose your fuel pressure.

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High idling, jumping while idling, idle air control valve code
ANSWER : Hi there. This can be caused by the issues that you mentioned or a number of other things. You need to make sure all of the connectors are making good contact. I would then need to know what codes are in the computer to know if this is a circuit issue or not. Most of the time, it is not the circuit but instead a vacuum leak.

If there is a vacuum leak, then the vehicle will act like this and the computer cannot control the idle. Most of the time it is a bad hose or an EGR valve that is stuck open. That is the most common cause for this. I typically remove the EGR to check it to feel the diaphragm on the bottom of it to see if it is moving correctly. If you need to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair your car’s idling issue.

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I put the wrong key in my car and a few weeks later my car just shut down and it will not start I believe it’s the computer but…
ANSWER : Hi there. What had happened is the wrong key set the security to the vehicle. This is to prevent the vehicle from starting with the wrong keys. Try removing the battery cables (+) and (-) for 13 minutes. During that time, put the original key in the ignition and turn it on. Activate everything in the car even though there is no power. Then remove the key and hook up the battery cables. The computer should have reset and reset the security. If the security is still being tripped, then I recommend seeking out a professional, such as one from Your Mechanic, to help you

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My car is idling very rough.
ANSWER : The idle air control valve is common for causing a rough idle in many cars, but it sounds like you have already corrected that. Another thing you may also want to check is the crankshaft position sensor. A crankshaft position sensor monitors the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. When this is faulty or not working properly, this will cause problems with the ignition system and generating spark transmission to the spark plugs resulting in starting problems, rough idling and other performance issues. You may also want to check the fuel pressure as low fuel pressure can also cause rough or poor idling if the fuel pattern being sprayed from the injectors is not consistent. This can also happen in the case of having dirty fuel injectors which may also interrupt the spray pattern of the injectors. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your car.

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Car is idling at high rpm’s and when the days are hot the car cranks but doesn’t turn on and also exhaust is smoking when i rev it
ANSWER : Hello – your symptoms suggest worn piston rings or valve stem seals (smoking), and a possible air leak in the intake, or idle air control valve sticking open (high idle). Both are signs of a higher-mileage engine with significant wear. I recommend an engine inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

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Replaced alternator on car 2 times each time shows it’s charging 14v let car run for a little bit then test drive and car voltage
ANSWER : There are reports that the replacement alternators will not communicate with the engine computer and will not charge correctly. I recommend using only the manufacturer approved replacement part. It can be new or remanufactured but approved for use in the vehicle. Some lower cost alternators on the aftermarket will have charging problems since they will not communicate with the ECM on the vehicle and will stop charging.

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