WTF is going on with my IDLE?

[vettekilr]

The last couple of days every now and then when I start the car the IAC is around 45 and the check engine light comes on and the car idles around 1100-1300,even though the CE light is on its not giving codes,it comes on and goes off maybe 10 secs. and comes back on, WTF.When I shut the car off and restart it, it goes back to 0 IAC and 750 idle and no check engine light.I bought a new IAC a couple of months ago and just put it in,the paper that came with it said to put it in and drive 40 MPH and it sets itself,is that right?

Could someone fill me in on this? THANX

 

[vettekilr]

Just went out and checked the car,samething high idle,and I noticed the FP was at 30.I shut the car off and restarted it, back to norml FP back at 40?WHAT GIVES?

 

[gn85]

Make sure you don't have a vacuum leak of some kind. That will not only make your fuel pressure go screwy, but will make your IAC fight for idle as well.