My cousin says it has to idle to temp, and the fans have to come on, than you turn it off, wait 10 minutes, and do the same thing again. How do I do it?

 

curious as to why you are looking to "reset" your idle? what is wrong w/ the car to need that? Some may not agree with me on this, but you shouldnt ever have to change the way the car came from the factory, unless youve made modifications.

 

It idles at 400 RPM, oil pressure, at that point, goes down to 150 KPA, and my alternator drops down to 10 volts.

 

I don't know much about that oil pressure part, but...

That doesn't sound too too horrible. Just so you know though, before anyone mentions messing with the minimum idle screw, know that once you do that, you'll have to readjust your TPS also, and reset your IAC. I wish I had never messed with mine.

Try cleaning the IAC, it may be stuck at a closed position.
Careful unscrewing it, take it slow, mine broke in half one time with the threaded end stuck inside the top of the throttle body. That wasn't fun getting out.

 

Yours idles at 400? I wish mine did. I can only tune mine down to about 1000.
Check your TPS and IAC, make sure that they are set right and clean. Don't mess with the idle screw if it hasn't been touched.

 

if youre idling at 400 RPMs, just adjusting your idle wont fix the problem. you need to find out why its idling so low, adjusting it will just bandaid the real issue.

 

It was idling fine until I last night, I didn't beat on it or anything, I was just coming home from dropping off my girlfriend, and it didn't want to idle. I changed the cap and rotor on wednesday, aswell as plugs. But it ran fine after that.