i put a GSR throttle body onto my skunk2 intake manifold.....now it surges like crazy.....it goes from 1000 rpms to 2000 rpms and then goes back and forth.....

when i had my stock throttle body on, it ran fine...i don't know if i bought a faulty throttle body or what? don't know what's going on

 

i can almost promsie u that its a vacuum leak does it cycle quickly?

 

Vacuum line
Is it throwing a code tho?

 

did you replace the TB gasket? check for leaks. and adjust the idle screw.

 

unplug your iacv and see if the idle changes. if so, your iacv is bad.

 

if you unplug it and it changes, it does not mean its bad. i have this same problem. and i have done that. and when i unplug it and idle's normal. but i took it off and cleaned it good and it is fine. gotta be a leak or something.

 

Im with the others on this, since you just changed the t/b and now have a idle problem it probably a vacuum leak.