i have a 59 apache that we just did an ls1 swap with. the engine came out of a 2000 camaro that was built and ran like a top with only 80k on the odom. the truck runs like a bat out of hell except it will no idle and dies...it seems like it will load up and the fuel vapors are strong. i am thinking that with returnless fuel system my fuel pump and regulator from speedway is which is pcm controlled is giving me to much fuel at idle and startup...any ideas would be appreciated.. thanks

 

Im not up on the cars too much, but the trucks were the return style in 2000. I would check your fuel pressure and make sure it is at 58 PSI with key on engine off(it might bleed down when the pump is not pumping). Are you doing your own tuning? Check to see if the flow value is setup for a returnless value. If vacuum/boost is referenced, the value will be a single number across the board. If it is not referenced it will be sloped. Dont forget the tip of the injector is sitting in the intake tract, and is under vacuum when it is idling. That basically adds to the rail pressure increasing your pressure by that much.