So about a week ago I bought my first third gen, a 91 firebird with 212,00 miles, completely stock except a k&n and dynomax exhaust. Earlier today I took apart the TBI to attempt the ultimate TBI mod (didn't go so well), and when I put it back together it doesn't run very well when it starts up. It dies when it starts unless I give it gas, and when idling at a stop the rpms drop till it dies. I tinkered with the fuel lines, and that seems to have helped it a little bit. So does anyone know why this would be happening? Thanks.

 

Recheck your vacuum connections. If you took your TBI apart a hose may be loose or broken afterwards.

 

Yup it turned out that the gasket between the throttle body and the fuel pods was in pieces and missing chunks, somehow I didn't notice. A couple new gaskets and it starts and runs better than it did before. Thanks!