How many of you... (FAIV question)

[CatchMe]

How many of you blocked off the Fast air idle valve? Im having some idle issues in which i've done everything but block this off. What happens with my idle is that when I free rev it up to 2300rpm+ It will stall out upon decel. Cant figure it out...

*I have no major boost leaks
*ISC is functioning properly
*BISS is set properly (dsmlink shows value of around 30@900rpm
*Im flowing .28 g/rev at idle which is correct airflow
*PLX wideband says 14.xx for a/f at idle so its not overly rich
*I am recurculating my BOV.
*This is unrelated to this problem but for reference, but I have a ACT lightweight flywheel, no balance shafts, no egrs. Had these with the EVO16G and never had a stall issue though.

This problem occured when I changed my turbo from a EVO 16g to a SBR gt12 along with a 3.5in intake dejon tool intake pipe. I also changed my spark plugs to NGK BPR7ES gapped to .028.

My last resort on fixing this problem is checking to see if some of my injector seals are leaking and blocking off my FAIV because i've seen some people have had success with that. Let me know what you guys think. Much thanks to those who take the time to help me.

EDIT: Also, if anyone has a good link on how to block off the FAIV it would be a great help - I have one that someone fabricates a block off plate...But I also hear you can Jb weld or fill certain ports which is what i'd rather do than fab up a plate. Thanks again!

 

[CatchMe]

Anyone? Help me out

 

[Maglin]

Well the FAIV is closed once the collant heats it up and melts the wax pellet that is in their. If you have removed the coolant lines from the Throttle body then that is your problem. If you take those off you HAVE to close up it's ports. If you live in a cold norther climate I would suggest that you leave the FAIV on as it is their for cold weather starts and if you disable it you will have to stay in the car to get it to idle for a few minutes. It's -20 outside here right now and I definitlty don't want to sit in a cold car having to kept my foot on the gas to kept my car running.

 

[CatchMe]

Thanks for the reply. The car is only rarely driven in the summer and all so its no big deal. I know how the FAIV works and all - I heard some peoples were malfunctioning and causing a bad idle. So what I did is took apart my throttle body and found that my TB shaft seals were shot...I mean almost non existant, they were quite bad. I wonder if thats enough of a leak to make my car stall upon free rev down? I guess we will find out - also im going to put my other FAIV on the Throttle body from my newer 97 2g throttle body. I have a old 91 on there right now from when I did the 6 bolt swap. I would have done a boost leak test but I need to go make a tester today for a 3.5in intlet turbo that I just put on and I have to go get a pressure tank and fill it up because I cant drive my car to the shop where they have a compressor right now.

BTW, according to dsmlink -

*TPS is working and calibrated perfectly (0% at idle)
*IdleSW is working correctly
*ISC motor is functioning with correct values
*g/rev at idle is .27 which is perfect but I did add to with the 50hz on the MAF slider because I have a vented valve cover.
***BUT my LTFT is stuck at the max at -12.5% which means a possible air leak.

So the only thing I can think of is these stupid TB shaft seals but is that a big enough leak? - what do you guys think?

Thanks again!

 

[tim_korn_99]

to answer your original question, i have my FIAV blocked off. It was my last resort to try and fix my idle problem, and, well, it fixed it. Some people have reported that when their FIAV is blocked, that their car won't idle right when its cold. There have been numerous times when its like 15 degrees outside, and i go out, start my car, and go back in the house to let it warm up. It works fine for me. Just a steady 850rpms all the time.
-Tim

 

[psychlow]

The problem may be related to your lightweight flywheel. This site's owner (Ludachris) had the same problems with a lightweight flywheel.

http://www.dsmtuners.com/forums/showthread.php?t=158190

 

[boostedinaz]

I am having a similar problem, but not as bad. My car had a mean vacuum leak at the TB and I could find it. I traced it to the TB shaft seals and that helped a ton. Now I have to get the BISS O ring to seal better and I should be fine. If that doesnt work then I will install and FIAV block off plate. This is a really nice piece that I got from a buddy and it looks great.

http://www.qprinc.com/fiav.htm

 

[moonstation2000]

DO I. I did both (new tb seals and fiav block off) at the same time and have no cold idle problems. now my car doesn't try to stall when i come to a stop. They are both very easy mods to do and i feel better knowing i have one less potential boost leak problem to worry about in the tb.

 

[jjsacidy]

once my isc was messed :thumbdown , but urs is good. another time i forgot a hose to the bov (no, not the recirc tube! it was a small one) horrible idle and killing problems and bad mpg . and another time the idle pos sensor connector came off. also turning the biss out enough and having the isc compensate by closing with all accessories off helped me quite a bit cuz then it can only open for loads. it stalled once since then at night with highbeams, stereo, rear defrost, blinker, braking, neutral, and fans going; and it was prob cuz it hit a hard note.

 

[Corman12345]

I blocked mine off, just used some jb weld, filled the hole up and placed it in the oven for about 45 min. Came out of the oven hard as a rock. The DSMLINK seems to be in control of the idle more now, before when you would set the idle to 800 it would idle about 200 rpm faster than that once it had warmed up. Now it idles right at 800. The only negative effects i have noticed is when it is really cold out, you need to add a little throttle to keep the idle up until it enters closed loop.

 

[psychlow]

but urs is good. another time i forgot a hose to the bov (no, not the recirc tube! it was a small one) horrible idle and killing problems and bad mpg .

Yeah, massive boost and vacuum leaks tend to do that.... :laugh:

 

[CatchMe]

The problem may be related to your lightweight flywheel. This site's owner (Ludachris) had the same problems with a lightweight flywheel.

http://www.dsmtuners.com/forums/showthread.php?t=158190

Good info. but it didnt stall out untill I added the big turbo, etc. - I had the flywheel in without any stalling problems before I changed my setup. Anyways - I just got done rebuilding my throttle body with all new seals. I will be putting my different FAIV on from my other 2G throttle body since they are the same as the FAIV on the 1G's. I'll update the thread for future reference. Thanks all

 

[boostedinaz]

Im still going to tr it on mine, but I have one concern. IF the FIAV and ISC are blocked I dont think there will any way for it to compensate for the A/C being turned on. Those who have it blocked did you block just the FIAV or did you block the entire lower portion. That plate I have gets rid of the entire lower portion and I dont know how that will work in the good ol AZ heat with no AC.

 

[tim_korn_99]

Im still going to tr it on mine, but I have one concern. IF the FIAV and ISC are blocked I dont think there will any way for it to compensate for the A/C being turned on. Those who have it blocked did you block just the FIAV or did you block the entire lower portion. That plate I have gets rid of the entire lower portion and I dont know how that will work in the good ol AZ heat with no AC.

I followed the link that the vfaq gives you for the FIAV block-off. I only blocked off the FIAV side of the lower portion with some jb weld. The ISC is still functional. It works fine, even in cold weather.
-Tim