I'm experiencing drivability problems with my 93' Civic DX Hatchback. At city driving speeds in 1-4th gears, the engine surges and it is absolutely a pain to drive. I recently replace the engined with a stock engine, only difference was it's a JDM. It also idles erratic when cold. I've tried relacing the Idle AIr Control vlave but that did nothing to help that. ANy advice is much appreciated.

Kenyon

 

check the ignition timing.