I have an 03' eclipse with the 2.4L. I recently had to pull the engine to fix a busted water pump bolt and now I have new issues. Since I put it back in when I let it sit over night or while at work when I go to start it, it will not start right away. It acts like It's not getting fuel and I have to crank it several times before it starts and runs rough until the fuel pressure comes up. Also the engine fans come on as soon as it starts and they run consantly, and the "service engine soon" light on the dash stays on. None of these problems were here before I pulled the engine. I went back and checked all the wiring and the fuses. I'm stumped!! Any ideas??

 

Sounds Like a Coolant temp sensor. If damaged, it will cause rough running, difficult starting, and probably leave your cooling system on for the duration. Pull it and see if it has a crack in it or if it has turned green. I don't think they are expensive, 12.00 or something like that.

 

Thanx, I'll check it out.