vibrating alot when cold

Hey everyone i have a 93 saturn sc1. The car vibrates badly at idle especially when it is cold. After warming up the vibrations become less severe. I have replaced all the engine mounts already. It has new spark plugs and there does not seem to be any vacuum leaks. Do you guys think i might need a new injector? Also the check engine light comes on sometimes but only for a few minutes and then shuts back off.

First place to start is to pull those codes. Throwing parts at the car hoping something sticks is not the way to fix anything. The link below will explain how to get the trouble codes.

http://www.differentracing.com/tech_articles/diag_info.html