I drive a 1987 GTA 5.7L 700R4 tranny. It used to drive ok, but know it turns off while driving. i can sometimes drive it ok with out it turnnig off, but sometimes will driving the car turns off even if im driving "normaly" (speedlimits). While driving when i get to a stop i have to keep one foot on the gas and the other on the brake.Otherwise if i let go of the gas my car turns off (revs fall all the way down). It turns on ok but even sometimes just trying to leave the car on, on P the revs just fall down and car turns off. I already change the IAC housing and the IAC as well.

 

A good starting point is to check the codes in the computer, then clear it. Check again after a it quits a couple of times. If you are getting different codes, you need a new chip. (Mine got a low oil pressure reading and would shut off).

 

So taking the car to computer diagnostics first???