Hello all, I'm am new to the forum but have owned a 96 Talon TSI AWD for about 5 years now. I just recently bought a 95 Eclipse GST have changed a few things bcause the previous owner did not get the sensors changed that were needed. My problem is Idle surge or high idle I have changed IAC checked the voltage going to the IAC. Double checked to make sure IAC is good and it is. Changed ECT sensor, and I am still getting a p0505 code. I messed with the BISS screw and got the idle to come down to about 750 or so but after the car idles for a while it will sometimes creep back up to about 1500-2000rpms. If anyone could point me in the right direction that would be great. The next step that I can think of is to check at the ECM but I really dont feel like tearing that thing out with it being tucked up under the dash the way it is, but if I have to I guess I will.

Thank you for any help.

 

You check the car side connections of the IAC?

 

there is an entire write-up on this on www.vfaq.com

 

might be the throttle position sensor

 

Ok now that I have some new info to go on and check. I have another question to ask and this is about the factory BOV and dump tube. The car is all stock but I have pulled the hose off the BOV and the dump tube with the car idling and obviously the car runs like crap. So I blocked the dump tube hole and the car idles ok.I noticed that there is air coming out of the BOV, is this normal at idle? I wouldnt think so being there should be a vacuum in the intake without the turbo spooling. Am I correct on this or is this something new I should know.

Thanks for any and all info.

 

air comming out where at the BOV. Though the dump tube or leaking through the flange. There shouldnt be any. The plastic stock ones are crap anyway. Alot of people will just upgrade to the 1g BOV. But you have to leave that dump tube connected to the intake. You cant vent the BOV on these cars

 

I guess my question is should the BOV be completely closed at idle. If so then something is wrong cause the valve inside the BOV is open about 1/4 inch or so but as soon as I open the throttle a little bit the valve slams completely shut then. Any ideas?

 

what bov do you have? If its not the stock one, you're spring is too weak. I had the same problem with my tial and it turned our i had a weaker spring in it. It would stay open all the way at idle.

 

It is the stock one. Did you have the same idling problems I have and throwing the P0505 CEL code?

 

Mine never threw a code because i was disconnecting the battery so much to work on it, but it still idled high. Actually it still does; especially in the winter. right now it idles around 2000 with the biss screw closed all the way. IMO its definitely the IAC/ISC. I just haven't had enough money to get a new one. I did find a website today that is selling brand new ones for $135 with free shipping. If i can find the web address i'll post it for ya. Hope that helps brother.