I'm trying to help out a friend that has a 2003 Vette with a stroked LS3 in it. The motor was built and the ecm was programmed at on place and installed at another where it is now. The build was done by a very well known and reputable shop so I dont want to discredit anyone, but it wont idle and nothing I do in the tune seems to help it, it's like it doesn't know how to control the LS3 throttlebody at idle... It will run down the road good and seems to have good power and the A/F ratio is good even at WOT, but no idle... Any ideas?