When I crank my car it idles up like it should and back down to300 to 400 real quick and then almost cuts off. Then it goes to 800 and does fine from thier. What could cause that.

 

I still got stock injectors

 

CTS?
IAC?
Loose nut behind the wheel

 

If it was intake leak, it should be continuous. Or such a leak that the vacuum would 'self seal' the leak. Pwr valve Canister or the fuel vapour canister system hoses? Block the hoses to tst.

Fuel pressure problem; regulator valve or its vacuum?

Check out the voltage level, how is it behaving?

Take out A/C and pwr steering to tst.

 

where is your iac valve hoses hooked up charged or non charged side and then i think the intake manifold hose that you have youshould try just have a filter on it (intake manifold) and have the hose on the intake tube caped
i dont know a whole lot about turbos but just a suggestion i know that is how my friend with a miata had it and a civic that i worked on had it

 

its on the charge side