“Check Engine Light” Car is not Accelerating

Check Engine Light flashing

The car’s check engine light is up and it is not accelerating.

If you have a check engine light on your dashboard and your car isn’t accelerating, it’s possible that you have a problem that has to be fixed. When there is a problem with the engine or one of its sensors, the check engine light normally illuminates.

In general, if the check engine light is up and the vehicle is not accelerating, there is a problem with one or more engine components. A shortage of gasoline, a damaged ignition coil, poor spark plugs, or a broken engine sensor can all cause the problem. A vacuum leak or a failing gasket, such as the head gasket, might also cause it.

If the check engine light illuminates in a modern vehicle, the ECU will reduce the power that the engine can produce in order to protect the engine; this is commonly referred to as ‘limp home mode.’ If your car isn’t accelerating as it should and the check engine light is on, you should get it checked out as soon as possible.

What Causes A Check Engine Light And A Car That Doesn’t Accelerate?

Here below we have provided you with the solution for Check engine light. Common causes involved in a blinking check engine light. So, let find it!

6 Most Common Causes

In general, if the check engine light illuminates, there is an engine problem, which is generally caused by a shortage of one or more of the following: fuel, air, fuel ignition, or compression. In this circumstance, the engine will limit its power output in order to safeguard the engine from harm.

The check engine light might pop up on for a range of factors. It typically indicates that there is a problem with the engine that is impacting how effectively it functions and requires immediate care.

1. Inadequate Fuel in the Engine

One of the most common causes of the check engine light and lack of acceleration is a shortage of gasoline or insufficient fuel pressure. A issue with the fuel delivery system, such as a clogged fuel filter, a leak in the fuel system, a malfunctioning fuel pump, or a damaged fuel injector, might cause the problem.

The fuel system is sealed and runs under high pressure to guarantee that gasoline is delivered to the cylinders on demand. A clogged fuel filter is one of the most prevalent causes of a fuel system obstruction. Filters can become clogged if they are not replaced on a regular basis or if dirt gets into the gasoline tank. When you accelerate aggressively and a rapid increase of gasoline is required, you may only realize that the fuel filter is restricting fuel delivery.

Typically, the ECU will illuminate the check engine light if the fuel rail pressure sensor detects a decline in fuel pressure. The ECU will also be programmed with the code P0087- Fuel Rail System Pressure.

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2. Cause number two: A faulty engine sensor.

A defective engine sensor relaying erroneous information back to the ECU might potentially cause a lack of accelerating power. The mass air flow sensor, manifold absolute pressure sensor, fuel pressure sensor, and oxygen sensors mounted in the exhaust are all sensors that contribute to engine performance and acceleration power.

If the mass air flow sensor does not accurately measure the airflow rate, it will impact the fuel to air ratio in the cylinder, resulting in a lack of power and an engine that runs too rich or too lean. The MAP sensor, in conjunction with the MAF sensor, determines the air density and rate of airflow into the engine. A defective MAP sensor will also have an impact on performance and can cause damage.

3. Faulty Ignition coil

A faulty ignition coil is a typical cause of the check engine light to illuminate, as well as a significant loss of acceleration power. The ignition coil is in charge of powering the spark plug, which initiates combustion in the associated engine cylinder. If the ignition coil has totally perished, the damaged cylinder will not be burning gasoline, causing the check engine light to illuminate. The engine will also be ‘down one cylinder,’ which will reduce the engine’s acceleration capability.

Rough engine run, engine misfiring, difficulty starting the engine, and a gas smell from the exhaust are all signs of a broken ignition coil, which may cause the check engine light to illuminate. Unrepaired ignition coils can damage engines, and unburned gasoline can damage the Catalytic Converter and oxygen sensors if it makes its way to the tailpipe.

By conducting a diagnostic with an OBD-II reader, you can typically determine which ignition coil is faulty. P0350 to P0356 are common error codes for faulty ignition coils or coil packs.

4. Faulty Fuel Injector

Another typical cause of a lack of acceleration and a check engine light is a faulty fuel injector or injectors.

A malfunctioning fuel injector is generally leaking or clogged. Fuel injectors are more likely to become clogged with time. If the engine is not working properly, this can be caused by a buildup of partially burned fuel around the tip of the injector. Injectors can also get clogged if the gasoline contains pollutants or if there is water vapor in the fuel lines, which causes corrosion and debris to accumulate in the fuel system.

A rough running engine, a strong stench of gasoline emanating from the exhaust, and an engine that is difficult to start or dies abruptly after starting are all indicators of a faulty fuel injector. An OBD-II scanner may be used to identify a faulty fuel injector, which can then be confirmed by removing and checking the injector. P0201–P0205 are common fuel injector fault codes, as are P0300 and P0299, which are generic misfire and lack of power codes.

5. The fifth cause is a leaking head gasket.

If the head gasket begins to leak, it can cause a variety of engine difficulties, including the activation of the check engine light and a loss of acceleration power.

A leaking head gasket will often result in compression loss in one or more engine cylinders. The purpose of the head gasket is to produce a seal between the cylinder head and the engine block. If it begins to leak, it might let coolant and engine oil into the cylinders. This leak will not turn on the check engine light, but it will cause misfires and a loss of oil and combustion pressure, which will turn on the check engine light.

Loss of coolant, engine overheating, loss of engine power, and low oil pressure are some of the most frequent signs of a failing head gasket.

These symptoms can result in a variety of error codes, including P0171 (fuel mix lean), P0522 (oil pressure difficulties), and P030x (engine misfires), among others.

6. Sixth cause: a vacuum leak

Another common cause of your car not accelerating when it has a check engine light is an engine vacuum leak. A vacuum leak causes a decrease of combustion pressure, which reduces the amount of power produced by the engine.

Unmetered air can potentially enter the manifold if there is a vacuum leak. Unmetered air is air that has not passed through the air filter and mass airflow sensor before entering the engine. This extra air will change the fuel-to-air ratio required for combustion, leading the engine to run lean, resulting in decreased power and possibly engine misfires.

Vacuum leaks may occur in a variety of locations throughout the engine, and are often caused by a leaky gasket or rubber hose. If the leak causes an issue such as a cylinder misfire, spark plug breakage, or unburned gasoline reaching one of the oxygen sensors, the check engine light will on.

What’s Next:

How Do I Repair A Check Engine Light When My Car Isn’t Accelerating?

If your car’s check engine light is up and it is not accelerating, there are a few basic tests you may perform to assist narrow down the cause of the problem.

When the check engine light illuminates, an engine fault code is typically kept in the ECU. This is triggered by an out-of-range value reported by an engine sensor.

The first step is to perform a diagnostic that will scan any error codes that have been recorded in the ECU memory. This may be accomplished with the use of an OBD-II error code reader.

If this shows any codes, it will assist to lead you in the right path.

Here are some common things to look for.

1. Inspect the fuel system.

If the error code indicates that there is a problem with fuel pressure or that the engine is running low, there might be a blockage or leak in the fuel system. Begin by replacing the fuel filter and making sure you can hear the fuel pump working when the ignition is switched on. Remove the injectors and inspect them for obstructions or leaks, such as carbon buildup on the tips.

2. Inspect the spark plugs.

If there are engine misfire codes present, such as P0301 through P0304, this might suggest a spark plug problem. Examine the condition of each spark plug. Examine the area for the existence of carbon deposits and oil. If the spark plugs appear to be in good condition, check that the ignition coil for each plug is operational and snugly placed when installed.

3. Look for a faulty engine sensor.

A defective engine sensor will often display an error code indicating that it is not providing data within the required range. Check that the wire and connector to the sensor are not damaged and that everything is tight. The engine should then be restarted to remove the fault from the ECU.

If the error repeats immediately, consider replacing the sensor with a new one.

4. Check the levels of oil and coolant.

If the coolant or engine oil levels are extremely low and there are no evident leaks, it might be a sign of a failing head gasket. Check the oil’s condition; if coolant has seeped into it, you’ll notice a brown milky mixture under the oil filler cap or on the dipstick. When the engine is turned on and there is white or blue smoke coming from the exhaust, it usually means the engine is burning coolant or oil. If there is a leak in the head gasket, both will enter the engine cylinders and burn off.

5. Examine for vacuum leaks.

A vacuum leak can sometimes be blamed for a lack of power. Look for fractures in the intake manifold. If the engine has a turbo, inspect the numerous hoses leading to and from the turbo for splits or leaks.

If the joints are leaking, you may see a little spray of oil surrounding them. It’s also a good idea to remove and inspect the EGR valve for clogs and leaks. If there are no evident leaks, remove the intake manifold and ensure that all seals and gaskets are in excellent shape and firmly placed.

FAQ Check Engine Light

Q.1) Can a clogged fuel filter reduce acceleration?

Yes, a clogged fuel filter can stifle acceleration by limiting the amount of gasoline reaching the fuel injectors. When you depress the gas pedal, the amount of fuel required to enhance engine power output increases significantly. If the gasoline filter becomes clogged, the amount of fuel that reaches the fuel pump is reduced.

Typically, the gasoline filter must be nearly entirely blocked for acceleration to be affected, and you may only notice the effect when accelerating fast. If there is a major shortage of fuel getting to the fuel rail, an engine issue code (P0193 – Fuel Rail Pressure Sensor Circuit High Input) will be generated, and the ECU may respond by limiting the engine’s power output to prevent serious misfires. A check engine light will also illuminate on the dashboard to highlight the problem.

Q.2) Can faulty spark plugs cause your car to stall?

Yes, faulty spark plugs will impair your vehicle’s acceleration and overall power output. This can be caused by a lack of gasoline ignition caused by a poor spark, resulting in incomplete fuel combustion.

If you have one or more faulty spark plugs, you may notice that the engine is difficult to start, that there are frequent misfires or hesitations, and that you are consuming more gasoline than usual.

Q.3) Why does my car hesitate when I step on the gas?

If your car hesitates when you step on the throttle, this might indicate a problem with the fuel system, air intake, or gasoline ignition system. A lack of acceleration can be caused by a variety of factors. Defective or clogged fuel injectors, a clogged air filter, a clogged fuel filter, a faulty MAF sensor, faulty ignition coils, poor spark plugs, and even a clogged catalytic converter are among the most prevalent.

The easiest technique to figure out why your car is stalling is to connect an OBD-II diagnostic scanner and check for engine problem codes. This will notify you whether an engine sensor is defective or if the engine is misfiring due to a malfunctioning injector or ignition coil.


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