Q: Throttle Positions VS Voltage Fluctuation

asked by on December 09, 2016

More obvious at night! Engine runs smoothly until the throttle becomes more demanding. Tach indicates RPM fluctuations,1 to 3 hundred, as more acceleration is required on upgrades; cruise or manual. Headlights and dash lights indicate a voltage fluctuation upon slight increase of accelerator demand on upgrade.

My car has 95000 miles.
My car has an automatic transmission.

Instrument Voltage Regulator Replacement $207.87 - $439.61 Get a Quote

This may be related to a couple of different possibilities such as a faulty throttle position sensor or potentially a faulty instrument voltage regulator. 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. Based upon the inputs from the sensor reading your foot’s position on the pedal, 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.

The instrument voltage regulator regulates the voltage supplied to the various gauges in your vehicle’s dash. When this is not working properly, this may cause the gauges in your dash to dim or flicker erratically or in some cases provide false readings. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your instrument voltage regulator.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I adjust the height of the shoulder belt?
The front driver and passenger seats have adjustable shoulder belts on the three-point seat belts. This allows the belts to be adjusted vertically. To adjust the shoulder belt, locate the belt guide, which will be on the inside of the...
Oil pump, replace or clean? I am installing a remanufactured engine?
You should look into buying a new one (https://www.yourmechanic.com/article/how-to-buy-a-good-quality-oil-pump) - especially with the age of your car. A used oil pump may not pump as good as a new one and may save you a lot of work if the...
What wires do I connect to the starter
The black and orange striped wire goes with the red wires behind nut with the big starter cable. The small, tan and red striped one goes to the small terminal. If you are still having trouble, a technician from YourMechanic...
brake noise at low speeds
Hello. Thank you for writing in. Typically minor noises from the brakes when the vehicle is moving slowly is normal. Brake dust and dirt is one of the most common. Eventually this debris is rubbed off by the brake pads...
Car making loud whooping sound
Hi there. I believe that the puddle/start of the noise was simply a coincidence. It does sound like you may have a wheel bearing failing. Rotate the tires front to back and see if that changes the location of the...
How much should it cost to replace front bumper
Hi there. Unfortunately, our mobile mechanics do not provide body work, which replacing a bumper falls into that category. It might be better for you to contact a local body shop to install your bumper, and check other front end...
Over filled oil gears shift late on turns. Will draining excess resolve issue?
Hello, thank you for writing in. There are several things that can happen when you overfill the oil in your engine. The damages can range from high oil pressures (and stress on the system), to complete engine failure. With that...
Oil light is on car full of oil runs smooth but oil light comes on
Hi there. When a motor is replaced, sometimes electrical sensors that relay information to the ECU have problems in communication and can cause multiple electrical problems as you've described. However, it's also possible this is mechanical, caused by a faulty...
Hissing sound from exhaust area?
There are a number of things this could relate to however depending on specifically where the noise is coming from may indicate different issues. Typically, a hissing sound coming from the exhaust (https://www.yourmechanic.com/services/noise-from-engine-or-exhaust-inspection) may indicate a potential coolant leak, resulting...

Related articles

How Are Car Wires Protected From Damage?
The highest tech cars can contain miles of electrical wiring. Wires must be secured and protected from heat and debris in order to work properly.
P2119 OBD-II Trouble Code: Throttle Actuator Control Throttle Body Range/Performance
P2119 code definition Throttle Actuator Control Throttle Body Range/Performance What the P2119 code means This code indicates that the throttle valve is...
How to Replace an Intake Air Temperature Sensor
An air temperature sensor, or air charge temperature sensor, signals a car’s computer about the air-to-fuel ratio. Replacing one requires few tools.