mcgojosh

Hey, I have a ls6 I swaped into a 2001 s10. It starts really rough when cold, I have to kind of help it along. Then it seems to idle fine. But once I give it some gas or shut it off it won't idle anymore when i re start it. I have a 1999 4.8l truck harness I modified to work, but I kept the case grounded o2 sensors. I'm wondering if this could be the problem, should I re-wire it itrun isolated ground o2's. I'm using a 2002 ecm. Thanks.
And if anyone has any other Ideas as to why it wont run, I'd appreciate it.