II just swapped a B series TB on my D series y8 head swap and the car is idleing at 1350 with the TB screw all the way down. Is this a problem? Is there another way to adjust it? BTW the tps is adjusted to .48 idle.

 

Put stock one back on. No need for the new one.

 

Does the B series throttle body have a Fast Idle Thermal Valve on the bottom of it? If it does I'm willing to bet its stuck open causing the idle to rise.

If there is no FITV then I would look into a vacuum leak around the throttle body gasket.

 

I cant put the old one back on because its cracked. N I thought I got it fixed but now Im having an issue of sputtering until the car is warmed up. Also when I lift the cold air intake up a little bit the car dies.