its probably the "kickdown" cable or arm, to shift gears according to how much pressure you have on the acelerator
There are two cables. One is the Throttle valve (TV) cable and that should go from the throttle linkage to the transmission. It will pop off the throttle arm and there is one bolt holding the cable housing to the transmission. take it out the bolt and unhook the linkage and replace the cable making sure to snap it back on at the throttle arm. The other cable is the for shifting and it should attach to a lever arm on the side of your transmission and go to the shifter linkage. If you are under the car and have someone shift with the car off you will see the the arm moving disconnect it from both ends of the cable and replace.
It connects the steering rack to the steering arm at the wheel hub.
The neutral safety switch is on the drivers side of the transmission. It is a black box where the shifter arm connects to the transmission.
Had same problem with my 92 MGM. One possibility, a detent arm is attached to the throttle. A rubber grommet holds it in place. This may have deterioriated and caused the arm to become loose. Its located right next to throttle. Also, the detent arm can be adjusted. It is the connection between throttle and transmission. Have a qualified mechanic check this adjustment. Failure to correct could damage transmission. You can get those grommets at a parts store. They come in a package of assorted sizes.
The elbow connects the upper arm with the lower arm.
Center link
the Drag link
Your arm connects and lets you move your shoulder, elbow, and wrist.
Because the arm that the shift cable connects to and the arm that connects to the throttle cable (for automatic downshifts) have corroded and siezed together. These two arms sit on top of the transmission under the battery (which needs to be removed along with the battery box for access) and are supposed to move independantly of each other, but when they corrode and sieze and you step on the gas, the throttle cable ends up pulling the shift cable and causing it to pop out of drive. Take the battery and box out, and you will see the two arms attached to the cables. Use lots of WD-40 or PB Blaster on the arms, let it soak, and work the arms free.
The arm.
The shoulder.
The joints connects the arm to the upper body.