Just swapped my blown h23a1 with a h23a3. After warm up the idle goes too low and the car dies. Starts and runs great otherwise. Also gonna rebuild the a1 if anyone has any suggestions.

 

Check you iacv and your fast air idle on the throttle body. Also you may want to make sure the coolant system is bleed. Idle screw messed with on the tb? Vaccuum leak? Its most likly one of those. You can do a leak down and compression check to assure its not the block which I don't think it would be.