My car revs it’s rpms when at park and drives itself to 25 mph without pressure on the gas pedal
So when I start my car up it spits and struggles to come alive, when I put it in park the car wants to rev up the engine and rpms, and when the car is in drive it drives itself slowly upto 25 mph without any pressure on the gas pedal. What could be the problem with that?
My car has 240000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
This may be a sign of a failing throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. The sensor is usually located on the throttle plate so that it can directly monitor the position of the throttle. The ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal. I would suggest having a professional from YourMechanic come to your home to diagnose your throttle control system.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
RPM fluctuation is a common issue for cars with faulty spark plugs as they fire the fuel with the pistons. If they wear out, your acceleration slows, and jerking and misfire start occurring, which, in combination, causes poor fuel economy and vibrations.
This is a common problem when the idle air control module is not functioning as it should. This is a component that helps to monitor air/fuel mixture at idle speed. When this is not working properly, this causes an imbalance in the air/fuel mixture resulting in intermittent or abnormal idling as you`ve described.
If your engine revs up as you press down on the gas but your vehicle doesn`t accelerate as much as you`d expect, you may be dealing with transmission slipping. If you`ve ever tried to accelerate on ice, where your engine revs but your vehicle goes nowhere, you know the feeling.
The reason it will not go over 2500 rpm is because the computer is in limp mode. This mode is for when the computer has a failure in it. Limp mode will trigger if there is an issue with one of the vehicle`s systems that the manufacturer suspects would cause major problems.
When a cars rpm goes up and the car is not picking up speed, this usually means that there is a problem inside the transmission. The valve body, shift solenoids, and or clutches of the transmission probably had gone bad or are worn out to the point they are causing a transmission shifting issue.
Your engine may have more RPMS due to any of the following: Transmission fluid is leaking. Transmission slips when changing gears because of a bad clutch. Speed sensor isn`t working, and the car can`t switch gears.
When a throttle body is not functioning correctly, you`ll usually notice a distinctly poor or very low idle. If the problem is really severe, you might even begin stalling when coming to a stop or when the throttle is quickly pressed.
The Quick Fix:
Clean air filters and fuel injectors will reduce the strain on your car. An engaged emergency brake causes the brake to drag slowing down your car. Disengage the brake to solve this issue. Sometimes acceleration problems are just because of low fuel or poor quality of fuel.
Trouble accelerating can come from a few different engine issues. These include, but are not limited to, dirty fuel injectors, low fuel pressure, and restricted airflow. A problem with the mass airflow sensor, throttle position sensor, or engine speed sensor can also cause a car to have difficulty picking up speed.
Here are some possible reasons your RPM is going up and down while driving: Worn-out spark plugs. Vacuum leaks. Bad idle air control valve.
Your tachometer needle will bounce up and down if your engine has a vacuum leak. The vacuum created in the combustion chamber is used as a power source, and, as such, it is routed through the engine to various locations using vacuum hoses. Over time, Collins Auto Care advises that these hoses can start to leak.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
My car revs it’s rpms when at park and drives itself to 25 mph without pressure on the gas pedal
ANSWER : This may be a sign of a failing throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. The sensor is usually located on the throttle plate so that it can directly monitor the position of the throttle. The ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal. I would suggest having a professional from YourMechanic come to your home to diagnose your throttle control system.
My car gas pedal seems stuck when pressing on it while in park or drive 1994 Honda Accord
ANSWER : Hi there – I believe the throttle body on your engine is worn out, specifically the throttle sensor portion of the unit (internal component). It needs to be replaced. I recommend a throttle body inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.
Car won’t rev or go when pushing gas pedal. Only revs up in neutral or park unless you work with it to keep it revving
ANSWER : Hello. The first task in solving this problem is to extract problem codes that are set, whether the Check Engine light is on or not. There are several problems which could cause this behavior, such as a bad throttle position sensor, fuel supply issues (low fuel pressure), or a dirty or bad mass air flow sensor. Problem codes will narrow the cause more quickly, and help avoid replacing parts that are not the problem. If you need to have a certified technician from YourMechanic can come to your car’s location to diagnose the gas pedal problem and follow through with repairs.
When I’m driving, sometimes the car over revs and jerks when I shift gears after the cars been on for a while
ANSWER : Hi There,
What you are describing may be a result of a faulty speed sensor, potentially low transmission fluid or a even a faulty transmission control solenoid. As your vehicle travels down the road, the computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshifts and downshifts by sending a signal to one of several shift solenoids. These transmission solenoids have spring-loaded plungers inside them, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes these plungers to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road. The computer controls the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. In some cases, the Engine Control Unit (ECU) can control the solenoid’s plunger by turning the ground circuit on and off. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your transmission.
What you are describing may be a result of a faulty speed sensor, potentially low transmission fluid or a even a faulty transmission control solenoid. As your vehicle travels down the road, the computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshifts and downshifts by sending a signal to one of several shift solenoids. These transmission solenoids have spring-loaded plungers inside them, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes these plungers to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road. The computer controls the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. In some cases, the Engine Control Unit (ECU) can control the solenoid’s plunger by turning the ground circuit on and off. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your transmission.
Car is accelerating without pushing gas, full rev when placed in park, should I drive it home from work? 28 miles away, oceanside
ANSWER : Hi there. This issue is typically caused by a malfunction of the cruise control system or throttle control. However it can also be caused by something as simple as the carpet or floor mats pressing down on the accelerator accidentally. If you start your car and the throttle continues to accelerate, I would highly recommend not driving the vehicle home; as it’s unsafe to drive. I would double check the floor mat to make sure that’s not the problem and start the car to see if the issue continues. If it does not, drive home careful and get the car to a mechanic as soon as possible.
The engine of the car runs, but when I push the gas pedal it does not accelerate, and the engine does not rev.
ANSWER : Hello. It sounds like you may have an issue with your throttle position sensor. This sensor sends a reference voltage to your power-train control module, which uses that to determine ignition timing and fuel trims. If the power-train control module is not detecting the proper signal from the throttle position sensor, the engine may not accelerate properly. It’s probably a good idea for you to have a professional mobile mechanic come to your location and complete a car is slow to accelerate inspection first, so they can pinpoint what is causing this issue to occur and they will recommend the right repairs be completed.
When I drive my car for about ten minutes, the gas pedal does not accelerate anymore, non of the gears work.
ANSWER : Hi there. There seems to be an issue with the ignition switch on your vehicle. The engine should shut off when the key is in the ’OFF’ position. I recommend seeking out a professional, such as one from Your Mechanic, to help you troubleshoot the ignition switch and related electrical circuits.
My cars RPMs rev up and down
ANSWER : Hello, and thank you for writing in. Typically when the engine behaves like this, you are looking at an air issue. You will want to focus in on the air intake, mainly the throttle and throttle position sensor. You may also want to look into the exhaust and the oxygen sensors. You should then look into vacuum leaks which can be tested relatively easily. From there you will want to look into the fuel pressure and the fuel injectors. If this system checks out, then you can turn your attention to the ignition system. Only further testing will tell. For more help with diagnostics, contact our service department to schedule an appointment.
