Check your fuel pressure, pumps, and hopefully your injectors are okay.
This sounds a lot like my newly acquired 58k mile 90. I believe I have it traced down to a faulty fuel pump, which is good, because they're inexpensive, and an easy job. But I'll know when the car comes back from paint.
Here is some information for you to start with.
http://www.zr1specialist.com/HAT%20W...in%20Place.pdf
http://www.zr1specialist.com/HAT%20W...eplacement.pdf
http://www.zr1specialist.com/HAT%20W...20Shooting.pdf