The nearest manual I have for your car is for 1988 thru 1993 full sized Chryslers. (I have driven my share of old used vehicles, too.) I was scratching my head trying to think of what could have happened to cause the event you described. At first, I thought maybe a return spring broke or came off, but then that would not repair itself and be "normal" again as you described. There are two spring loads that tend to return the accelerator pedal. These are the return spring and a small bias spring in the throttle position sensor. I do not think it was either of these.

Do you have cruise control? This gadget can do exactly what you described. Its control is a set of switches in the steering wheel and can be accidentally bumped. Lets say that you accidentally activated it (turned it on) and now it is armed to take control of pulling the throttle. Hitting the resume button or accelerate button sends it into action pulling on the throttle. Depending on what the speed setting was, it will continue to open the throttle until that speed is attained and then throttle back to maintain speed. Sometimes, the system overshoots the mark. The sensation you get is a sinking pedal when the control takes over. Next comes the interesting part. Activating the brake switch temporarily releases the cruise control, so when you stepped on the brake and pushed it far enough to operate the brake switch, the cruise control let go and returned the accelerator pedal operation back to you. The system will behave normally, but if you did not turn off the cruise control, it was still armed and ready to do the same thing again. I do not know all the details of your particular model; The cruise control may or may not disarm when the ignition switch is turned off.

There should be a light on the instrument panel that turns on when the cruise control is armed. It may be a green lighted word, "cruise". On a car of that age, I believe the instrument panel is lighted with incandescent bulbs. These do burn out and the cruise lamp could have been missing. If you notice that a lamp or 2 is out on the dash, re-lamp the entire dash. For instrument panels lighted with light bulbs, it a good idea to re-lamp every 5 years.

Whatever the case, its best you have a qualified mechanic look into that misbehaving throttle. Let us know what you find. Do you have cruise control?

Now, about your other problem. We need to know more. Was it a vibration from the wheels or was it the engine cutting out, misfiring, and generally misbehaving? If its wheel vibration that appears as speed is increased, that can be caused by several things such as wheel balance weights getting knocked off. If you have drum brakes on the rear, these should have a small balance weight tack welded on the outer surface of the drum. Sometimes, these get knocked off during service work and go un-noticed. No amount of wheel balancing wil cure the problem until the drums are rebalanced. If the braking surface (of the drums) are 1/2 worn down, it makes economic sense to replace the drums rather than to try to find a balancing service.

But first, you need to determine the source of the problem before it can be attacked. Trying to fix the wrong problem does not work.

Hi, I brought it to the mechanic and they could find no reason for the pedal going to the floor. I don't have cruise control, nor do I have extra mats on the floor. The only thing they could tell me was that sometimes the throttle sticks. I think that's one of the things they said though I'm not sure about that since we discussed so many possible causes it is hard to remember them all.

The bumping of the wheel is because of a bent rim. Not bent enough for the wheel to fly off but bent enough to make that noise. Must have happened when I hit a pothole. I have the local junk yards looking for a replacement now.

If you hit a pot hole hard enough to bend a wheel (rim) and if this is a front wheel, have the alignment checked when you mount the replacement wheel. There is a possibility that the wheel bearing was damaged also and this may not show up immediately. Do not be surprised that after about 5000 miles, that wheel bearing begins to make a grumbling noise. If it does, it has failed and needs to be replaced immediately. Do not drive a failing wheel bearing to its ultimate failure of breaking up or seizing. That can result in a catastrophic event.

When getting a wheel from a salvage yard, check it for wear around the mounting holes. The beveled wheel nut should contact the wheel before it bottoms out on the face of the drum (or rotor). You'll notice that the wheel is not flat on its backside, but is bumped out around the mounting holes. It effectively forms a very stiff cone washer and the nut should be in contact with the wheel before the nut comes into contact with the face of the drum (or rotor). That part of the wheel is supposed to flex a bit as the nut is tightened and acts as a very stiff spring washer. It keeps the nut from loosening. If the beveled hole in the wheel is worn too large, it allows the nut to bottom out before becoming tight against the wheel; and the nut is in danger of coming loose. With the nut bottomed out, but, the wheel not snug against the beveled nut, micro motions of the wheel can work the nut loose.

Funny you say that about the bearing because I had that same concern. But my mechanic assured me the bearing looked okay. He suspects the rim got bent by the place that changed the front shocks and did the alignment because prior to that the rim wasn't bent. He would know since he change my tires only the week before - winter to summer. Of course, you can't accuse someone of that unless you're positive.