That is my current problem, car is not properly tuned. Very disappointed. So now I need to find someone or a company that can supply a proper tune.
It not only idles badly, it won't idle until the car reaches temp. It barely runs in rpms ranges 3500 or less, nothing but misses, bogs, backfires and just a general mess. Above 3500 it all goes away and car runs like a beast but it runs so poorly under 3500 it is difficult to get it to 3500.
The car was warm when I went to pick it up, so when I started it, it idled up right away. I took it up and down the street and noticed it was rough but just thought it was me. Once I got it home (flatbed) and started and tried to drive car today.... car would not start and hold idle, it just dies. I stayed in car feathered throttle to keep it running until engine up to temp, then it would idle.
So..... I waited several months for this, not at all happy but now I have a new project.