Ok, Starting up when it's been shut off for a couple hours it starts fine but it idles very erratic. I imagine from the sound of the engine it's idling at about 1000 rpms and then seems like it drops about 500 rpms before revving back up to 1000 again. After a while of driving it'll go away. What could be the problem of this? Thanks again.

 

Have you checked the ECU, for any codes?

Checked the coolant level, and tried bleeding the cooling system for trapped air?

Go hear for more places to look:

http://geocities.com/chipman_13/ecu.html

 

Ok, I think I know the problem. On the site it mentions the A/T shifter postion. I have a manual but my ecu went bad and I replaced it with a ecu from an automatic civic, (same year, same motor, same options, just it was an auto). Could that be the problem with the idle? Cold starts it'll rev up and down but when it's hot it doesn't do that but sometimes when i release the brake pedal it will do it again occasionally. When it's running good it does seem to be running a bit high tho. Thanks for any info again Appreciate it.