After modifications, car won't idle

[930Chas]

I have just finished installing k27, kokeln i/c and ghl headers and exhaust. The car started which made me darn happy, especially considering my meager mechanic skills, but now it won't idle. Damn. So I talked to Stephen, and he felt that I had a leak in one of the hoses to the intercooler. Well, from what I can tell, all the hoses are definitely snug. I'm not going to bother him again with this piddly arse problem. So, does anyone have any ideas. It also hesitates a little under acceleration, like it isn't getting enough gas. Do i need to adjust the fuel mixture? And if so, how is that done? Thanks for any help and ideas.