Weird start-up idle

[Keith]

I thought this might go away when I installed my new CA18ET, but it\'s still there.....Started about 2 years ago with old motor.
What it does is only at first start-up of the day, or after it\'s been sitting for over 8-10 hrs.
When I first crank it, it idles perfectly and around 1200-1500 rpms like it should when cold.  After about 45 seconds the idle will drop suddenly to around 800-900 and run kinda rough.  It will do this for about 30 seconds then all of a sudden it will bounce back up to 1200-1500 and idle perfectly smooth again.
Now, with my brand new CA18ET I also replaced all sensors except:
Detonation sensor, Air flow meter(it\'s about 3 yrs old), I.A.A., I.A.S., Air Regulator(It\'s about 3 yrs old), Crank angle sensor(it\'s about 4 yrs old), TPS, and ECU.
All other sensors, vacuum lines gaskets, and emissions crap is new.
I may run codes while it\'s doing it to see if it picks up anything, but otherwise......no codes.
Any ideas????

[YellowPreludeR]

1200 is a HIGH idle.  My ca20et idles at about 800-900 with nothing major as a rough idle. Its a little rough, but I need to get a new air regulator and some other timing / air/fuel mixtures settled out.

[Keith]

The air regulator is what makes it idle around 1200-1500 when cold....... which is normal according to the FSM.  After about 5 minutes when the car starts warming up the idle slowly goes and stays at 750-800.
Any ideas on my problem???

[bartc_j]

hmm might be the air regulator...might have some kind of faulty het elemen in it

[Keith]

How would I test the air regulator?  It makes the car idle up when cold, and idle normal once it warms up so that part of is working fine.....so I guess if it is the air regulator it would be the electrical part of it??