I'm thinking about getting a vtec motor and putting it into a 1990 civic hb. I was wondering if I need the ECU for that car?

 

What motor? And what trim is your car? And dont listen to the horrible bashing you are gonna recieve.....

EDIT: IF you are going obd1 you can get a chipped p28 and that will run any motor(sohc vtec or dohc vtec)

If you are staying obd0 you can get a pr3 ecu for a dohc. Or a 90 ex ecu and run turboedit with it an activate vtec.

Just give some more info though