Thread: bov opening at idle

ok guys on the s14 we changed the spring in the tial about 2 weeks ago from the stock 11lb spring to a 7lb spring. the car ran fine up untill 2 days ago when it is searching for idle. i noticed that the tial bov is opening up at idle (it shouldnt do that right?). well i taped the openings closed with blue painters tape and the car idles perfect. is it possible that the spring shrunk/got softer or something and causing the bov to open at like 3lb or something? any reason why it would barely be doing this if it ran fine for 2 weeks?

or is it something completely different? i did not find any boost or vacuum leaks, i searched it very good.

My bov runs that way but it's recirc'd. Maybe a weak vacuum source ?

well its been running off the same vac source since installed and never had this issue before.

A BOV being open at idle isn't necessarily incorrect. However the placement of your MAF in relation to the BOV is likely the problem. If you're not going to recirculate your BOV, you need to have it before the MAF, not after.

ya guys i know and understand all that with recirculating and bov's. if that was the problem wouldnt it have occured since the beginning and not 2 days ago. the cars has had about 5k miles after the swap with this setup.

the bov will open and is suppose to open under any vacuum situation,the only one i can think that doesnt vent at idle is the ssqv. sc guys hate that bov.

so could something have happend that is creating more vacuum making the bov open more than usual? because it is completely opening all the way causing the irratic idle.

I think you might be running into a situation where the self learning of the ECU took about 2 weeks to get your in trouble.

Why did you switch out the spring? Were you experiencing compressor surge?

Where is your MAF? It is before or after the BOV?

well the 11lb spring was to much and was causing compressor surge.. the maf is in the stock location off the intake pipe

You have to recirculate it or run the maf after the bov.

It is odd that you weren't experiencing problems from a huge amount of unmetered air before.