hey there,
Likely you have bad injectors... There are many threads on that procedure with pictures and you could get a video from Haibeck himself (
www.zr1specialist.com).
The one thing we say to owners is you have to drive the car so you don't get issues. Not just starting it once a month, but opening up the secondary injectors.
Things to change out are the injectors and fuel filters... That is a good start and "should" fix your issue. Spark plug wires can be tested once you have the plenum off and you can check your coil pack too. (coil packs are $155 for the set and injectors / gaskets are under $500)
Get your gaskets from
www.jerrysgaskets.com (very reasonably priced) Coil packs are on ebay and the injectors are bosch.
Keep us updated
David