[LMP]

First are you able to retreive any diagnostic codes? in '94, This is OBD1 and there is a trick. If not know, come back and ask.
Is the SES (service engine soon) light on at any moment? THis looks as one of 2 things:
- faulty throttle position sensor (TPS) - should give a code 21 or 22. This code will stop cruise from engaging, also will stop 4th gear and torque converter clutch.
- faulty fuel pressure regulator or fuel pump...although this one is suggested very often, I'd check for other things first.

...I also read with great interest the thread " 1995 Bonneville - stalls and windows fail" . In case you have no clue related to the above, this ground problem under the carpet is an interesting (although ?!?*?#*) option.....