we decided to swap my tiny manifold with and larger one off a d15 90 si. i still have my stock motor. we hooked everything up the same, go to start it and RPMs just jump with out touching the gas gas. i was told it might be a throttle gaskets or the manifold gasket. what eles could it be ???

 

Anything that can let air into the manifold when the throttle blade is closed. Go find the crossed wires or vacuum leak.

Not enough information to accurately diagnose. What model do you have, what EXACTLY has been done to the wiring and intake tract. DPFI to MPFI?? Upgrading and HF throttle body??

 

throttle cable

 

it is the throttle position sensor on the old school the two outers need to be switched other wise the ecu thinks it is at wide open throttle. try it out and let me know.

 

as for old I mean 88-91 and if you are putting it on a 92 it goes as i said

 

What motor?