Just swapped out my old h2a4 trans for another, replaced clutch tob and pressure plate, my problem is that when the car is running I cannot get it into any gear but when the car is off I can run threw all gears fine. What can cause this?

 

clutch is not disengaging.

 

What can be the reasoning behind that?

 

either it was installed incorrectly or more likely the clutch hydraulic system needs to be bled.

 

Cable trans, I guess I'll probably have to pull the tranny then

 

What is an h2a4 out of? I cannot find it on any list of Honda trans, found M2A4, H2A5, H2U4, H2C4, P2A4 and those are out of accord/preludes and have a hydraulically activated clutch...

 

sorry didn't mention it was swapped from hydro to cable. Pretty sure the trans is out of a prelude

 

must be an oddball since it appears on no parts lists of Euro, UK, US and Asian transmissions.
Make sure your cable adaptation to the transmission is working properly and giving enough movement.