I own a 91 z28, just recently i started havin a problem with it. When i went to my sons school to pick him up, i parked my car and after about 5 mins heard a loud bang like something had hit my car. I got out and looked and didnt see anything so i started the car up. It ran fine so i shut it off, when he come outside and we went to leave when i put the car in gear the engine started to surge. I got it home and noticed that it only surges when its in reverse or a drive gear, but not in park or neutral. I have asked a few friends and have got 2 different opinions, one is the governor went bad and the other was the convertor went kaput. But i would think with the convertor gone it would do it all the time. If anyone has had this problem and figured out what it is i would be greatful for some input.
Thanks in advance.

 

Do a for surging and stalling.
There's about 5 million posts on TPI motors doing this.