What is the idle at when it does run correctly? If it is too high it is actually bypassing the idle circuit IIRC. Truthfully, I would ditch the Carter but there are a few ppl on here that know quite a bit about fixing them. Mine started going out and I just found a Weber. Took all of about two hours to install and adjust and I don't regret it the least.
1997 TJ, 5" IRO front with 4.5" HD IRO WJ rear, 35x12.5x15 Mickey Thompson MTZ, JKS disconnects