That sounds exaxtly like what happened to my 91 RS> I had the VATS bypassed at teh steering column by soldering in a resistor, but there is a second function in the VATS that I believe disables the fuel pump throuhg the ECM. LIsten to see if your fuel pump runs wehn you turn teh key to "On" (not start) I think if you don't hear it that indicates a VATS problem. I was lucky to know someone locally who specialized in vette and thirdgen electrical. He did some wiring and stuff to bypass. Not sure what. he was under the hood and in the areas around hte VATS and ECM. I think you can also disable it through reprogramming. check sith the folks at tbichips.com or
www.hawksthirdgenparts.com. tehy sell a VATS bypass module. Sorry i can't be more specific.