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Sudden acceleration

My car will suddenly accelerate, maybe 6-8 times a month. If I firmly and quickly press down on the gas pedal, it goes back to normal. A mechanic couldn’t figure out what was wrong. Someone suggested it was connected to the cruise control? anybody have any ideas?

What year is this Taurus?

Does this happen shortly after you have floored the pedal, say to merge onto a highway?
If yes, then I would suspect an issue with the throttle linkage, throttle body, or throttle motor sticking.

If you are sitting at idle at a street light, and then the car guns itself, then that’s going to have a cause either in the accelerator pedal, throttle motor, or somewhere else, where the computer thinks the pedal is telling it to open the throttle, when it actually isn’t.



No, it usually happens when I’m driving in town, between 25-35mph. ??? : ) Sounds like you know a bit about cars. With the info. I’ve given you, could it be linked to the cruise control? thanks for the reply. dg

2005 should be throttle by wire (ETC).

For your year, cruise control is just some software in the PCM and the buttons on the steering wheel. There’s no external servo to control the throttle because the throttle is already electronically controlled with its own built-in servo.
I think that you can move on from the cruise control theory.

There is still the inertial sensor and the input to the ECU to open the throttle. If this were happening routinely I might suggest unplugging the sensor as a test, but since it’s so intermittant that might won’t work.

To the OP: have you had the ECU chacked for stored trouble codes? I wouldn’t suspect one for this type of problem, but it’s always good to check.

Just thought it may have been connected since the cruise control stopped functioning at or around the same time. We have had codes pulled, all throttle arms/controls and linkage taken apart and lubed. I also replaced a part the mechanic told me may have been the culprit but I forget what it was called but is some kind of vacuum or air controlled thing that mounts on the engine. It did not make a difference. The car does not accelerate as often or as severe as it once did, but still occasionally.

You aren’t the first to complain. There seem to be several reasons, including the cruise control. Check it out at

Search for your 2005 Ford Taurus and “vehicle speed control”

That part might have been the idle air controller.

I made a stupid booboo by the way. The change in speed is not detected by a sensor, I believe it uses the Vehicle Speed Sensor signal for a reference. But the point is that there is a signal used by the ECU to drive the throttle and injectors that feeds the cruise control system, and the cruise control system must therefore be considered a suspect for sudden acceleration.