Rich:
ZR1's are very fussy about battery strength.
If the battery drops much below 12v all kinds of gremlins can jump out and bite you.
Getting a new battery is a must if yours is having charging issues.
Your idle is getting better, sounds like you've still got vacuum leaks.
It should normally idle at 850.
On my '90 I chased a vacuum leak for ages that was causing idle issues.
Turned out to be a vacuum connector just behind and under the throttle cables. It's hard to mess with because it's tucked underneath there and if it's not exactly right the damn thing leaks like a sieve.
It's a '90 model year only connector, GM realized it was not a brilliant design so they changed it in '91.
I was able to buy a new one from JeffVette (a.k.a. Jeff Flint) here on the forum. He has the worlds only supply of spares. After replacing mine, I decided if it ever gave me problems again that I'd re-engineer the connection and get rid of the #@!#$%%ing thing.
Idle aside, the running rough could mean many things. Fuel injectors, coils, wires, plugs all come to mind.
I'd highly recommend that someone familiar with these engines pay you a visit for a little diagnosis assistance.
Nothing is cheap for these cars, and I'd hate for you to just throw buckets of money at the car unless you had to.
Do you have a FSM (factory service manual) for this car?
It's an absolute necessity if you're going to work on this car yourself.
If not, here's a link:
http://www.helminc.com/helm/product2...X5WR6BV30U2TQ1
TomC
"Crabs"