so any ideas what i should do next? take the idle air off and replace it? or is it my computer? i just figured if the idle air was sticking then unplugging the MAF the idle would remain the same.

 

Take it out and clean it first. If fails then replace it.

 

okay so what you are saying is that if the IAC is failed it is normal for it to idle where it is supposed to be when i unplug the MAF and then jump up when i plug it back in?

 

Concentrate on the IACV first. I'm saying take out the IACV and clean it good. Put it back disconnect battery and see if it idles better. If not IACV is no good. It's stuck in the open position which allows air to bypass through the throttle valve (butterfly), hence, you got high idle.

 

I'm not sure if the Sc400 has a cable at the throttle body that controls the line pressure like the Sc300 does, but you may want to check.

If the trans cable is not adjusted properly the throttle butterfly might not close.

If someone takes the transmission cable off the throttle body for whatever reason, it's easy to hook it back up and be out of adjustment.

I actually did this awhile back.

 

That's only if you overtighen the throttle cable.

 

This might explain why the car is taking off on itself or is that just a product of the 4k idle?

 

Its easy fix and check. Look at throtlle cable linkage where its attached to the lever, does it look tight and pulled?

 

will look at it today its at the shop i work at im just the lowly service advisor not an actual mechanic but the mechanics are just as lost as i am theyve looked it all over and dont know what part i should buy i'll make sure they actually pull the IAC out they prettymuch assured me that it was not the IAC sticking because with the MAF unplugged it settles down to normal but from what you guys say thats normal for a broken IAC

 

did you fix the problem?