Accelerator pedal goes to the floor sporadically while driving

Question

One of my cars is a 1987 Chrysler LeBaron GTS, which originally belonged to my mother, and has only 30,000 miles on it. Occasionally, the accelerator pedal will go to the floor. (My mother took excellent care of the car - garaged -so much so that it looks factory new.) The first time this happened to me was last winter when I was coming off the exit ramp of the interstate. It was a long downhill ride to the light. I lightly put my foot on the accelerator to keep at the 30 mph exit speed, and suddenly the pad went right to the floor. As soon as I applied the break the car slowed down. It freaked me out but I chalked it up as an anomaly due to icy roads even though the car had studded snow tires (2 years old). Then, a few months later it happened again while on the highway. I immediately took it to my mechanic who could find nothing wrong. Even the floor mats were not in the way. Despite all that this still happens, and has been increasing in frequency to the point where I no longer drive the car. Today, my sister went on line and read at the Car Guy that the first sign of a transmission going is when the accelerator pedal goes straight to the floor. Is this true and if so can anything be done short of replacing the transmission? Quite honestly, I don't want to waste money on a car this old and will sell it to a collector instead. But, I happen to like the car and the way it handles, so would prefer to keep it if it doesn't cost me an arm and leg to do so. Any ideas besides this that can help me figure this out? Thanks for any advice and ideas.

Answer 1

From your description, it sounds like there is an issue with the cruise control. If the cruise control "thought" you wanted to accelerate for whatever reason, it would do exactly as you stated and peg the gas to the floor. Then, when you apply the brakes, it would tell the cruise to shut down. I don't remember how the cruise is actuated on the LeBaron, but IIRC, it's on the turn signal. I wouldn't know if it would be the control or the unit which would be causing the issue, but needless to say, I think I'd unplug it (in the engine bay) until you can have a mechanic look at it. The last thing you need is for uncontrolled acceleration to be going on when you are just trying to tool down the lane. Could get ugly really quick.