I agree, sounds like the vacuum shut off diaphram has a leak.
If you have a vacuum pump, remove the hose that got knocked off the last time, hook up the pump and apply 20 inches of vacuum
it should hold for at least a minute.
If the vacuum doesn't hold you'll need to replace the shut off diaphram, It is an easy job but one that you can screw up if you are not careful.
I'm sure you can get the part at fast lane on this site. Then you remove the three screws that hold the diaphram in, being sure not to drop them. Then pull the diaphram very gently toward the fire wall while rotating the diapram toward the passenger side until it releases. Take the new diaphram and put it in with the vacuum connection facing uo and gently push it into the pump and rotate it toward the passenger side until it pops in, then rotate it back to it's normal orientation.
DO NOT push the diaphram into the pump and just install the screws.
This has the same effect as holding the accelerator to the floor and when you start it you will have a very bad day.
ASE Master Tech