ALright heres the layout. 97 ex with a newly swapped Jdm OBD1 b16a. After finally gettin the thing to start up. The rpms jump to 7,000rpms then back down, then all the way back up to 7K. I've by-passed the IAC no luck. Even ruled out the cuise control actuator. I can even take my fingers and block off the the 2 ports inside the trottle body for IAC and the fast idle crap, and the engine still revs that high. Motor sounds fine no abnormal noises, except the high reving. Also the engine was recieved as almost a bare block(no harness or sensors) and was out of time when recieved. other than that every vac line is good. this is like my 9th engine swap--4th honda one and an exact copy of another swap I did with a b16a in a 97 HX. So any help would be appreciated as I have never encountered this problem before. thanks

 

sounds like a vacuum leak
have you checked the intake manifold gasket or injector seals?