What Causes Honda Accord To Not Accelerate?

The most common causes for a Honda Accord to not accelerate properly are dirty or failing fuel injectors, faulty sensors, failing fuel pumps, clogged catalytic converters, and worn transmission components.

The Honda Accord is known for its reliability, performance, and fuel economy. However, like any vehicle, it can develop issues that affect acceleration over time. When an Accord lacks power when accelerating, it’s usually due to problems with the fuel, air intake, ignition, or exhaust systems. Fortunately, many acceleration issues can be resolved with simple maintenance and repairs.

Dirty or Failing Fuel Injectors

Fuel injectors are critical in regulating the fuel mixture in the engine of a Honda Accord. These components can become clogged with debris over time and fail to provide the optimal amount of fuel when accelerating.

Symptoms of dirty or failing injectors include:

  1. Engine hesitation under acceleration
  2. Rough idle
  3. Decreased fuel economy
  4. Failed emissions tests

Replacing dirty fuel injectors can frequently solve acceleration problems and restore engine performance. This necessitates the removal of the old injectors and the installation of new ones that have been properly tuned for your Accord’s engine. Proper fuel injector maintenance, including the use of fuel injector cleaners, can help to extend their life.

Faulty Sensors

Modern vehicles, such as the Honda Accord, rely on a variety of sensors to regulate performance. Sensors that fail can send incorrect data to the vehicle’s computer, causing acceleration issues.

Two key sensors that commonly fail and inhibit acceleration are:

Throttle Position Sensor

This small sensor detects the position of the throttle valve and transmits it to the vehicle’s computer. If it fails, the computer will not know how far the throttle is opened when the accelerator is pressed. This can result in an incorrect fuel mixture and hesitation when accelerating.

Honda Accord not accelerate
Honda Accord not accelerate

Mass Airflow Sensor

This sensor measures the amount of air that enters the engine. This information is used by the computer to calculate how much fuel is required. Low readings from faulty mass airflow sensors can result in fuel starvation and poor acceleration.

To restore engine performance, faulty throttle position sensors and mass airflow sensors must be replaced and calibrated. Typically, diagnostic trouble codes indicate a faulty sensor.

Failing Fuel Pump

The fuel pump delivers gasoline from the tank to the engine at the optimal pressure. Over time, fuel pump impellers wear down and reduce fuel pressure. Symptoms of a failing in-tank fuel pump include:

  1. Long cranking before starting
  2. Sputtering acceleration
  3. Lack of power uphill

Before replacing the fuel pump, check the fuel pressure with a gauge. The readings below specifications indicate a bad pump unable to supply adequate fuel for acceleration.

Clogged Catalytic Converter

The catalytic converter plays a vital emissions control role by converting pollutants into less harmful gasses. However, carbon deposits can gradually restrict exhaust flow through the converter. Signs of a clogged catalytic converter include:

  1. Reduced acceleration
  2. Drop in fuel economy
  3. Foul exhaust odor

Removing and inspecting the catalytic converter is needed to verify the blockage. If heavily contaminated, the converter requires replacement to restore acceleration and engine efficiency.

Worn Transmission Parts

Like any complex mechanical system, an Accord’s transmission has many parts subject to wear. Faulty gears, shafts, bands, or clutches inside the transmission can inhibit its ability to properly transfer engine power to the wheels. Warning signs include:

  1. Delayed acceleration
  2. Hard shifts
  3. Slipping gears
Honda Accord to not accelerate
Honda Accord to not accelerate

Diagnosing malfunctioning transmissions requires specialized skills and equipment. Rebuilding or replacing the transmission may be necessary to resolve poor acceleration caused by internal wear or damage. Proper maintenance and fluid changes reduce the likelihood of transmission failure.

Additional Acceleration Issues

While dirty fuel injectors, failing pumps, and faulty sensors account for many acceleration problems, there are some less common issues that can also cause an Accord to lose power when accelerating. Being aware of these other potential causes can aid in diagnosing the problem.

Air Intake Leaks

For optimal combustion, the air intake system feeds the engine with clean, filtered outside air. Unmetered air enters the engine through leaks in intake components such as vacuum hoses, air filter housing, or turbocharger pipes. Intake leak symptoms include:

  1. Engine hesitates or stalls, especially at higher RPMs
  2. Rough idle
  3. Check engine light with lean air fuel ratio trouble codes

Inspecting intake components for cracks or loose connections can reveal leaks. Replacing deteriorated vacuum hoses and tightening loose clamps will prevent unmetered air from entering the intake and restore smooth acceleration.

Clogged Fuel Filter

A clogged fuel filter prevents the proper amount of gasoline from reaching the injectors. This results in fuel starvation under heavy acceleration. Warning signs include:

  1. Loss of power when accelerating
  2. Engine stumbles or misfires when accelerating
  3. Check engine light with fuel delivery error codes

If acceleration problems occur after many miles, replacing the fuel filter is a likely fix. Use manufacturer recommended replacement intervals as a guideline.

Failing Ignition System

Problems with ignition components like spark plugs, wires, or ignition coils will inhibit proper combustion necessary for acceleration. Common symptoms include:

  1. Misfires, hesitation, and power loss when accelerating
  2. Occasional backfiring
  3. Check engine light with cylinder misfire codes

Inspect all ignition wires for cracking or loose connections. Use a spark tester to check for weak spark from coils or plugs. Replacement of worn ignition components will restore engine performance.

Exhaust Leaks

Cracks or loose connections in the exhaust manifold or piping before the oxygen sensors allow oxygen to mix with exhaust gases. This provides a false lean reading to the computer, which reduces fuel delivery. Signs of an exhaust leak include:

  1. Hesitation and stumbling upon acceleration
  2. Rattling or hissing sound from the exhaust area
  3. Oxygen sensor trouble codes

Use a visual inspection along with a stethoscope to isolate exhaust leaks. Promptly repair leaks with high temperature epoxy or by tightening flange connections to prevent oxygen sensor issues and acceleration problems.

Identifying less common sources like these takes diligent inspections and testing. But addressing the actual cause, however obscure, is key to restoring strong and consistent acceleration in an Accord.

How Do I Fix My Car Not Accelerating?

Cleaning or replacing air and fuel filters, repairing faulty sensors, inspecting engine components such as spark plugs, and testing the fuel pump and injectors are the most common fixes for poor car acceleration. Begin by looking for trouble codes to help you diagnose the problem. 

If no codes are present, check each component involved in delivering air and fuel to the engine methodically. Inspect the wiring, spark plugs, fuel pump, and transmission, as well as the fuel pressure and volume. 

Repair any flaws discovered during testing. If the problem persists after performing basic engine checks, a professional mechanic may be required to perform additional sensor, catalytic converter, or internal engine diagnostics. Addressing acceleration issues as soon as possible can help to prevent more extensive damage.

What Sensors Can Cause Power Loss?

The mass air flow (MAF) sensor and the throttle position (TPS) sensor are two of the most common sensors that can cause an engine to lose power when accelerating. The MAF measures the volume of incoming air so that the computer can calculate how much fuel is required. If it fails, the engine may receive too much or too little fuel, resulting in hesitation and power loss. 

The TPS monitors the position of the throttle valve and relays it to the computer. If the readings are incorrect, the proper air/fuel mix will be compromised. If oxygen sensors provide incorrect exhaust data to the computer, they can also cause power loss.

What Are The 3 Causes Of Acceleration?

The top three most common causes of poor acceleration are:

  1. Clogged air filter – Restricted airflow leads to improper fuel mixtures. Replacing a dirty air filter can restore acceleration.
  2. Failing fuel pump – As impellers wear down, fuel pressure drops. This starves the engine of fuel needed for power. Testing fuel pressure and volume will diagnose a weak pump.
  3. Dirty fuel injectors – Contaminants on injectors inhibit optimal fuel atomization. This leads to hesitation under acceleration. Using fuel injector cleaners or replacing injectors improves performance.

Other issues like worn spark plugs, defective sensors, and transmission problems can also inhibit acceleration, but these are the most prevalent causes.


Accelerating up to speed and maintaining momentum are essential capabilities for any vehicle. When acceleration issues arise, identifying and addressing the cause promptly helps restore an Accord’s performance and prevent further damage. 

Knowledge of the most common acceleration problems these models experience allows drivers to be informed of warning signs and when to seek professional assistance. With proper maintenance and timely repairs when needed, Honda Accords can continue providing years of reliable transportation.

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Ammar Masoud

I have had a long and fulfilling career in the automotive industry, primarily with Honda and Acura. With 15 years of experience as a Honda service technician, I became highly skilled in repair and maintenance, gaining a deep understanding of these vehicles. After many years in the automotive field, I decided to embark on a second career in industrial manufacturing. It was a significant change, but I found that the skills I had honed in the automotive industry were incredibly valuable in my new role. In my current position in industrial manufacturing, the demand for quality workmanship and meticulous attention to detail is paramount. Fortunately, these are traits that I have cultivated throughout my years in the automotive industry. I take pride in applying these skills to meet the high standards expected in the manufacturing sector.