finished a zc swap on my friends 91 dx hatch. it will idle, but it is erratic like an iac motor. we tried using an iac from another motor we had, and it still does the same thing. any ideas?

 

Should do a bit of searching cuz lots of the basic problems with start-up could be fixed. As always make sure ur vacum lines are all connected correctly. Check all wiring for shorts/grounds and such. Make sure no unplugged plugs and then check for fuel/spark. Also was the check engine light on? If so check the code.
Theres lots it could be...but it's easy to fix if u know wat to look for.

DOHC zc's FTW!

Also check thezcr.com
civic4g.com