12 Causes of a Car That Won’t Accelerate (and How to Fix Each)
Have you ever experienced your car suddenly losing acceleration, leaving you in a dangerous situation on the highway? You’re not alone.
In this article, we’ll explore the common causes of this issue and help you understand what’s happening under the hood so you can get your car back up to speed.
Reasons Your Car Won’t Accelerate When You Push the Gas
Acceleration problems are a common occurrence in high mileage vehicles. But typically, there are no serious or immediate concerns regarding major engine problems. As with any car problem, potential causes that are minor should be checked first in order to locate the issue and possibly fix it as well.
Below are some of the most common culprits to a lack of acceleration. The reasons are many so if you’re not completely comfortable troubleshooting a car that won’t accelerate, we recommend you take your vehicle to a reliable mechanic and let him properly diagnose the issue.
Read Also: Symptoms of a Faulty Transmission Speed Sensor
#1 – Mass Air Flow Sensor Clogged or Malfunctioned
The mass air flow sensor (or meter) is located and attached to the inlet air cleaner. Since the function of the air flow sensor is to measure air mass that is flowing into air intake, a clogged or bad mass air flow sensor could send the wrong data to the engine ECU for calculating the air fuel mixture.
A very common symptom of an air flow meter malfunction is car that struggles to pick up speed.
How to Fix: Clean or replace the MAF sensor.
#2 – Oxygen Sensor Malfunction
An oxygen sensor (aka O2 sensor) is device whose function is to monitor the exhaust emissions of the vehicle so that it can analyze the air-fuel ratio going through the engine of that vehicle.
To make a long story short, a car needs a proper amount of fuel in order for the fuel to burn properly in the combustion cylinders so that it may run smoothly and may accelerate as required.
This sensor sends the information about the amount of fuel being used to the computer unit of the engine and if this sensor get damaged, then the engine of that vehicle will have no idea what ratio of air-fuel mixture to use which may result in a fuel rich mixture.
This can cause the slow acceleration of the vehicle even with the accelerator pedal completely pressed making it unreliable when it’s needed.
How to Fix: Using an automotive scan tool, determine which sensor is malfunctioning. Replace the O2 sensor.
#3 – Malfunction of TPS
The basic principle of the throttle position sensor (TPS) is to detect the throttle valve opening angle which is controlled by accelerator pedal. Then the TPS will send this data to the ECU.
If the TPS malfunctions, the engine speed cannot be controlled by the accelerator pedal and engine speed will increase or decrease without any press or depress the pedal.
How to Fix: Replace the throttle position sensor.
#4 – Dirty or Clogged Fuel Filter
A dirty or clogged fuel filter is another reason for a car not accelerating like it’s supposed to when required to do so.
With a dirty fuel filter, the engine won’t be getting enough fuel which means that the vehicle won’t be giving the acceleration performance that it should. Replace the fuel filter as soon as possible.
How to Fix: Replace the fuel filter.
#5 – Clogged or Dirty Air Filters
Just like a fuel filter provides the engine with the clean fuel, an air filter provides the engine of a vehicle with clean air to be used in the air-fuel mixture which will be sent to the combustion chambers to burn.
If an air filter is clogged, then the engine won’t get the right air-fuel mixture resulting in slow acceleration. Replace the air filter as soon as possible.
How to Fix: Replace the air filter. If you have a reusable air filter like K&N, follow the directions on cleaning it.
#6 – Bad Fuel Injector
Fuel injectors are responsible for delivering fuel to the engine, and if they’re not functioning properly, your car will likely not be able to accelerate properly.
A dirty, clogged, damaged, or faulty fuel injector may restrict the flow of fuel to the engine, which can result in poor acceleration, hesitation, or even stalling.
How to Fix: Use a diagnostic scan tool to read error codes from the car’s computer. If the error code indicates a problem with the fuel injector, you can try cleaning it with a fuel injector cleaner. If cleaning doesn’t work, replace the fuel injector.
#7 – Limp Mode
Limp mode is a safety feature that is designed to protect your engine from damage. If your car’s computer detects a problem with the engine, it may put the car into limp mode, which limits the engine’s power and speed.
This undoubtedly will cause your car to have acceleration issues, and may also be accompanied by a flashing check engine light.
How to Fix: Using an OBD2 scanner, scan the car’s computer for fault codes to determine what exactly is causing the vehicle to go into limp mode.
#8 – Faulty Fuel Pump
The fuel pump is responsible for delivering fuel from the gas tank to the engine. If it’s not functioning properly, it can cause a lack of fuel pressure, which can lead to poor acceleration. Symptoms of a bad fuel pump include sputtering or stalling while driving, difficulty starting the engine, and a decrease in fuel efficiency.
How to Fix: Replace the fuel pump.
#9 – Timing Belt
This component is as it sounds. The timing belt is something like a VIP in the list key of components of an engine. If this belt is off even by 1 tooth, it may cause some pretty notable acceleration problems.
How to Fix: Replace the timing belt.
#10 – Slipping Clutch
If you have a manual transmission, a slipping clutch can cause acceleration problems. This happens when the clutch disc fails to engage properly with the flywheel, causing what feels like your car has lost power while driving. It’s similar to a person trying to run on ice.
Signs of a slipping clutch include a burning smell, difficulty shifting gears, and poor acceleration.
How to Fix: Replace the clutch.
#11 – ECU
The ECU, or engine control unit, is responsible for regulating the performance of your car’s engine. If it’s malfunctioning in some way, it could be causing your car to have trouble accelerating. A faulty ECU can cause a variety of other issues, including misfires and poor fuel economy.
How to Fix: Repair or replace the ECU.
#12 – Clogged Exhaust
Two major components of your car’s exhaust system are your catalytic converter and muffler. If either one of these becomes clogged or damaged, this can restrict exhaust flow and lead to a reduction in engine power and acceleration.
This is especially the case with turbocharged vehicles which require proper exhaust flow to work as intended.
How to Fix: Check all components of the exhaust system to look for clogged or damaged parts. Replace if necessary.
Checking for Trouble Codes
If your car won’t accelerate, one of the first things you should look for is the Check Engine light. This light will come on if there is a problem with your car’s engine or emissions system. It’s worth mentioning that the Check Engine light does not always mean that there’s a major problem. Sometimes, it can be a minor issue that can be easily fixed.
To check for trouble codes, you will need an OBD2 scanner. This is a device that plugs into your car’s OBD2 port and reads the codes stored in your car’s computer. Once you’ve connected the scanner, you can retrieve the trouble codes and get a better idea of what is causing your car to not accelerate properly.
Once you see what trouble codes have been stored, you can use them for diagnosis. These codes will give you a better idea of what is causing your car to not accelerate properly.
But the fact is that trouble codes don’t always pinpoint the exact problem. In some cases, the codes may be related to a minor issue that can be easily fixed. In other cases, the codes may indicate a major problem that requires immediate attention.
If you’re unsure what the codes mean, have a mechanic diagnose further – don’t rely on the codes alone.
Acceleration Problems’ Impact on Fuel Economy
When your car won’t accelerate properly, it can have a significant impact on your fuel economy. Poor fuel economy is a common symptom of a car that won’t accelerate as it should.
You may think that if your car is accelerating poorly, it’s using less gas so your fuel economy should be better. But the opposite can actually happen!
If your car is struggling to accelerate, it means that your engine is working harder than it should, which can lead to increased fuel consumption.
He’s known for his attention to detail and problem-solving skills and enjoys coming up with out-of-the box solutions when the situation requires it.
When he's not troubleshooting customers' cars, you'll most likely find him working on his current project ('96 Bronco) or cooking Italian food for his family.
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So I have an 05 Acura rsx type s and have been have acceleration issue so 1 2 3 gears I accelerate just fine but 456 if I push the gas more then 1/3 of the way down the rpms go up but I go no where as if I were in neutral one I let of and reapply within that 1/3 I average without issue. I’ve changed the tps checked alternator just need an idea I’ve read so many things that are all over the board any help would be great !!
You likely have a worn clutch or misaligned which is causing slipping. The longer you let it go, the worse the problem will get.
Well that’s ain’t good how much does a clutch usually cost
Not cheap since labor is about 5-6 hours. Independent shop about $600-$1000 total for an OEM clutch replacement. Dealership would probably be double that.
I have a 2017 Mini Cooper. It’s a stick shift and it used to accelerate easily and effortlessly, but now it struggles whenever I press the gas pedal. I got an oil changed and it didn’t fix it. I don’t don’t what to do. Any advice?
I have a 2000 Mercury Grand Marque. After driving 200 or more miles and the car is stressed going up a long stretch of highway the car stalls. By letting my foot off the accelerator it will gradually pick up speed when car is going down hill or when the highway levels off. Three dealers have indicated no problem after full diagnostic evaluation. I’ve replaced fuel filter, all plugs, three coils, with no results. What to do?
I have not replaced the Mass Air Flow Sensor, or the oxygen sensor, or the throttle position sensor.
Hi, I was driving on the highway when my gas finished. I got gas back in. Started the car a Honda Pilot 2004, it started normal but it won’t accelate despite pressing the gas pedal (accelerator) to the fullest. Got a new fuel pump, got the injector nozzles cleaned and it still won’t accelate. What could be the likely issues please
I have a 96 Pontiac Sunfire. It’s a standard and when I shift gears it sputters acting like it’s not getting enough gas. What does this mean
First thing to do is check for any vacuum leaks in the engine. A rubber hose might have popped off, cracked, or gotten a tear in it. After that, check simple things like the air filter and spark plugs. You can also use a diagnostic tool to scan for any trouble codes the computer stored to help pinpoint the problem.
My 2007 Hyundai Santa Fe will not accelerate.No smell just won’t go pass 20 mph any thoughts. Retired and limited budget.
It could be any of the issues above or even something else. Best thing to do is to get it scanned for any trouble codes by a local mechanic.
I have a 2003 Ford 250 7.3L Diesel
When it gets hot outside, my truck seems to lose acceleration and power. I can still drive, but with my foot to the floor, it barely accelerates. I can get going about 50km/h.
If I turn it off, and turn it on again, it works just fine. Anywhere from 5ft to 50km. Doesn’t have any problems at all when it’s cooler outside. And turning the key off, then on again seems to fix the problem. However sometimes it’s just a few seconds then it loses power/acceleration again.
Sounds like the truck is putting itself in limp mode. See this: http://cartreatments.com/limp-mode/
You’ll want to scan for any DTCs using an OBD2 scanner.
I have a 05 Ford focus when I fire it up on a morning I can put my foot to the floor and the rev needle dosent move it takes about 5mins then it will rev but there is no power in any of the gears it struggles to get over 80 then as soon as I hit a hill it’s strait back down to 50/60 then take a 10mins to build it’s speed back up any ideas
I have FORD FOCUS CAR – Manual Gear Transmission system, Run 2,23,000 KMS.
Car is condition is good. All sensors are working.
From yesterday i found some variation in Odometer readings display when I accelerate Foot pedal Engine RPM increasing as earlier. But found variation in Speedo meter readings.
2000 RPM ~ 80-90 KMH (Earlier 100 KMPH)
3000 RPM ~ 100-105 KMPH (Earlier 120 KMPH
2 days before I replaced new FUEL PUMP unit. Not found any difference in Engine RPM (raise or lower the RPM by accelerate and decelerate).
Please advise me to inform our Mechanic to do repairs / replace required spares.
I have a 2006 Chevy HHR hit a rock knocked a hole in the oil pan patched it I put oil in it today got about a mile then it wouldn’t accelerate greater than 15-20mph then would just rev up I did spill a little oil like a doofus as I was filling it up but it didn’t burn no smoke I don’t know if maybe the oil could have gotten on a component and fried it or if it’s another issue entirely
Automatic corolla 2007, it accelerates smoothly up to 65km/hr then stop accelerating. It only allow acceleration after it decelerate to 25km/hr.
2011 ford fusion , driving normal then sudden lost of power , wont accelerate . but is all good after i shut it off and restart.
I’d get it scanned for any trouble codes asap. Your car may be in limp mode which is often reset after a restart.
http://cartreatments.com/limp-mode/
I drive a Honda V6 2003. After driving several miles, when I slow it won’t pick up speed until I turn off and restart the engine. My mechanic has not been able to detect the fault.
My car wont pick up any speed it will not let me go over 10 miles
Make sure this doesn’t apply: http://cartreatments.com/limp-mode/
2005 Altima, 178,000 mi Car will rev in park, when put in drive or reverse will glide forward or backward however when accelerating to actually drive will not go even with gas pedal pushed all the way down!!! Check engine light on. What could it be? Am going to have to have it towed.
My car struggles to pull away, it chug chugs for a couple of seconds even if I press the peddle down totally, sometimes feel like an airbubble that I’m pushing through, its so frustrating but when I drive fast it goes like a dream but the minute I slow down it takes forever to move back up. We replaced spark plugs and coil but no difference
I have a 1999 Toyota Solara. My check engine light flashed on and off a couple times when I tried to accelerate up a small incline. It was also very cold out that particular night. It has about 120k miles on it. We ran a code scanner but nothing came up. Any suggestions? It was struggling to accelerate and would stick at 2000 rpms. Then the check engine light would flash on and off.
If the check engine light was flashing, there should be at least 1 trouble code stored when you scan it. If the car simply wouldn’t go past 2000 RPM it could also be in limp mode signaling some major issues. I’d recommend getting it scanned again in case the scanner itself was faulty. Go to a local Autozone if needed as they’ll scan it for free.
My 2010 Nissan Altima has the same problem, did you ever figure it out ?
Mine is a 2003 Chevy Tahoe, I heard a singing sound, then it started jerking and then I had to press the gas petal all the way too the floor just too get in my driveway
You must not have been goin very fast then if you had the pedal all the way to the floor.
Hey my 2010 Altima is doing this now. Did you find out what it was?
Andreaz: i own a 2009 Xterra, same, same, NP starting it, but try and press on the gas, it goes like no where. was told it was rings and the likes, but it doesnt make any sense, problem i know, they have made these cars to darn complicated, and Mechs flat out do not know. even had it plugged into the ECM and codes dont tell much, multi cylinders misfiring…..well i knew that, and it doesnt say why. MAF sensor was replaced, still got problem. rive up engine at light, turns green and car goes no where, or a crawl at best, please help, what could it be? is it possible that it is for sure, not the trannie? now knowing just that would make me feel a bit better.
I have an 2008 Cadillac Escalade and it only goes 20 mph and does not reverse, I already replaced the solenoid. Do you know what could be the problem
Your vehicle may be in “limp mode” which is a safety precaution when the car’s computer recognized a serious issue with the engine or transmission. You should get it scanned for any trouble codes. I’m actually in the process of creating a new post on this topic but it unfortunately won’t be published for a few days.
I have 2009 VW Jetta sports wagon I just had a new water pump and knock sensor replaced and ever since then my car will drive normal until I go to Accelerate quickly it will start to jerk and bogged out almost coming to a stop when pedal is pressed to the floor what else could Cause this
The other day I was leaving the driveway with slippery roads. The wheels did spin as I was on a slop but did manage to get on the road. Immediately I noticed the ENGINE LIGHT, and Traction control lights on. I had slow acceleration after that and still do. When I restarted the engine, the ENGINE LIGHT is on and after I am in gear and moving the traction light stays on even on dry roads. Any thoughts? 2009 Camry 125Km
Your car may be in limp mode (can you shift through all gears?) or another serious issue. I’d recommend getting the check engine light code scanned asap.
For 8 months ive spent hundreds of dollars and still no result! Whenever I am sitting at a stop sign to accelerate or a stop light… whenever I mash my gas pedal it’s a horrible scrubbing sound and sometimes it will literally stop my car in it’s tracks!! My gas pedal has been checked to see if something was stuck…brakes has been checked… throttle body been cleaned… rotors been replaced brake pads…motor mounts… driving axel…but yet the same thing!!!!! I just found out my abs sensor is bad! My question is could that affect the acceleration! It’s very dangerous and its a scary feeling when driving my car!! It feels like metal…but will literally stop my car in it’s tracks whenever I accelerate after a stop!! #Help
Have you had your car scanned for any DTC (trouble) codes? A bad ABS sensor shouldn’t cause something like this.
Have a Mercury Mountaineer 2007, yesterday coming from shopping, my car was working normal, suddenly at a red light, stopped responding when tried to accelerate and stayed that way every stop light on my way back home, before get there, stop to buy some groceries. After that the car was back to normal.
Could be that your car is driven in very cold weather. Happens with most cars. However, after it warms up, the problem should be gone. If not, then it’s something else.
I have a 1999 Lincoln Town Car Signature Series and it will not accelerate when I press on the gas does this mean that the fuel filter needs to be changed
I have a Chevrolet aveo 2009 acceleration is very low even when I press on the gas to the floor and engine shakes when ac is turned on.can some one give me some advise please
I have a 2005 Honda Accord ivtec, 4 plugs. The current mileage is about 110000. I changed the gear box recently and since then the car experiences poor acceleration. When started, the car will run normally for about 30 minutes but once there is a little hold up and car was on and ac running problem starts. When I trottle the car will not accelerate and when I continue matching the trottle the car starts to shoot and often grounds to a halt. When I switch the car off and restart, the acceleration becomes normal for a while before the failure to accelerate repeats.
I have also noted that the car doesn’t easily accelerate beyond 100km/h. My technician attributed the problem to the raising switch which he brought out and cleaned. The problem stopped but reappears after some days of driving. I have also had to change the plugs and had the nozzles serviced. Please help me with useful information.Thank you.
Maybe have problem with automatic transmission
could be parking brake on 😉
I use a 2007 Camry,my battery ran down and after jump starting,the car came on and just won’t accelerate at all,flat on 0,the gas pedal seems for fancy,I asked a mechanic to check,he said fuel pump,and next thing he said the gas pedal has to be replaced that he found out the car pumps fuel just fine,I asked him to return the pedal and I’ll get back to him.
flat 0? mean the car even not run at idle?
I have a GWM florid 1.5
When I am on the freeway of any open road driving between 80-120 km/h with my foot on the gas , after a while it just slows down while my foot is pressing down on gas. Then when I leave the gas pedal and place my foot back on the gas pedal it accelerates again.
I have changed the fuel pump , there are no smells , no leaks on the ground and no emergency check lights comes on and no sound.
Please help
did you check catalytic converter? clogged check
I’ve got a 95 integra and when I give it gas it revs up but there’s hardly any pull. If It starts moving it starts vibrating unless I put it into the next gear, but I’m still maybe only going about 4mph
i have 2006 peugeot 407, it wont accelerate when i press the pedal. what is the cause please?
the engine light is on
check what the engine light code. The dtc will give you come clue
Toyota Scion won’t accelerate and won’t open up and when I got a light and it idle
My car is Mercedes c320, it will accelerate and after sometimes it ceases to until I turnoff the engine and start it again before it can accelerate again and the process starts all over. What is the possible cause of this?
I have a 06 Lincoln Mark LT 2WD. Its having issues while I accelerate it. It almost makes a “jumping motion” when it starts to bog down some. Not sure what is wrong with it. Cat. Converters have been cleared out, and plugs are good.
I have a 2012 Toyota Etios Liva drives normal for a while then just stops, motor is still running but when you push on the pedal it does nothing. I can shut the car off and restart it and I will drive fine again for a while. And the engine light on from that moment.
use scan tool check the code
I have Mazda Axela 2004, in traffic when I pressed accelarate, speed and RPM very slowly increase but after 3_4 second the RPM suddenly increase 3_4 thousand and the car speed very high, what is the problem???
I have a 2008 Hyundai Sonata. On two separate occasions after I started the car it would not accelerate or rev at all, though it would idle and move forward in idle. In both instances turning off the car and starting it again (rebooting it?) fixed the issue. Any ideas? And Thank you.
My question is I have a 2002 Honda Civic. The check engine light is on. Saying misfire in cylinder 2. I replaced spark plugs and air filter. My car will not accelerate it just revs. I’m afraid it’s transmission. What do you think
I have Toyota spacio, the acceleration doesn’t react quickly especially when the engine has been idle for sometime, but when the engine has warmed up its very ok. what could be the problem?
a 99 camry that has no check engine light on but will accelerate poorly and then when I press the gas pedal down to the floor I will smell a burning smell later
I have a 2001 hyundai Tiburon standard it drives good but sometimes i accelerate the pedal and it goes slow rpm goes to 3 and when it comes back down starts getting power can somebody help
2002 GMC Sonoma…truck goes into gear without hesitation or slippage, but will not accelerate over idle speed, maybe 5 mph. Engine races with acceleration but does not result in movement of the truck.
My daughters 2002 Infinite’s check engine light came on the other day and last night coming home her car wouldn’t accelerate over 60. When she got home it was running hot. What could it be?
My car acceletor dont picking up pickup…
Sometime it show some air licking type syptoms..
Why this happns.??
Hmmm.. am using Ford Fiesta 2011 model and for past 3 years I Ve been enjoying this car till I had the issue of overheating which has generated a lot of problems which I can’t even explain. They changed the gasket Nd so many parts of this car but the problem Stil persists. What should we do again to resolve this problem? Thanks.
cylinder head gasket?
i drive a 2011 toyota venza V6 acceleration is slow my 80 mph movess like a 45mph and consumes alot of fuel trust when i say alot.my wife drive 08 hyundai accent moves wey faster.at 50 and thats 1.6ltr engine
Hi.. My car is a 2006 Hyundai accent and it’s not accelerating in drive or in reverse it just lets me roll backwards there’s no awkward sound my car still starts up do you know what the problem might be?
My 2015 Kia Rio almost stops on me when I accelerate and it gets a little scary when I turn and it won’t go and a car is right behind me. It also does this when I change lanes
My car will go along fine at any speed, then suddenly it feels like the brake is applied, car slows down alot, have to gear down to fourth or third, floor it and eventually will pick up fuel and take off again. Replaced 2 ignition coils (used) about 5 months ago as was doing this before and worked good since, but has started acting up again. New plugs but not wires. 04 echo. Do you think it’s these again? Anything else it could be?
I have 07 Ford E350- V8 5.4L, replaced my compressor and on starting the car to fill gas. My car struggles to accelerate; engine working fine thou engine and throttle lights are both on. Need help here