bad fiav?

[vol96]

2g tsi, fwd, auto, bone stock
On cold start, car revs to about 2k rpm. RPMs then drop off, briefly settle around 1k then stalls. It takes 2-3 such starts before it will keep running. Then when I start driving, it has no low end power and I have to pump the gas pedal to get it to accelerate. Once it warms up its pretty much OK. By that I mean it starts up fine when warm and accelerates fine but the idle is very lumpy (like big cams).

Also when warm, if I pull a vacuum line it starts to miss and will eventually die. Shouldnt the idle increase if I pull a vacuum line and dont plug it?

Vacuum at warm idle is only 11.

I have no vacuum leaks.

I'm thinking maybe the FIAV is not moving enuf. I know it moves some because I took it off the TB, ran it under hot water and it did move. If its not moving enuf, I'm thinking its causing a miss which in turn reduces my vacuum.

Does that make sense?

 

[91-gsx]

It does sound like the FIAV on your car is not working like you said. But, before you buy another throttle body, I would check for boost leaks.. A leak anywhere before the Mass Air Flow Sensor will also make the car stall after start-up because of running too lean.. Worth a try because its always good to check for boost and vacuum leaks(which you have looked for and found none) before spending your hard earned money. Hope this helps. Later

 

[vol96]

You mean AFTER the MAF dont you?

 

[91-gsx]

You mean AFTER the MAF dont you?

I mean check for leaks from the turbo, lower intercooler pipe, intercooler, upper intercooler pipe, throttlebody and throttlebody seals, Intake manifold, fuel injector seals, PVC valve and hose...

 

[vol96]

Well I did boost leak test again. This time from IC input. BOV leaked like it wasnt there. So removed the BOV and plugged the hole with a sink drain plug. Stuffed it in there god and clamped it. Blew that sucker right out.....including the BOV sleeve. Tore apart the whole garage looking for it. Finally found it stuck in a pulley I had hanging from the ceiling.

Got the plumbing charged up to about 20psi before it blew. And had just enuf time to confirm no leaks...TB seals, injector orings, IM, BISS, EGR, IAC, PCV, all vac lines (only BOV and FPR connected).

I thought about using my impact screwdriver to plug the BOV hole 'cause it was the perfect size. But chickened out.

BTW, anybody mod their 2g BOV by putting a rubber washer in it?

 

[the_mork]

You can mod the 2g bov by putting it in backwards. Really you should just switch to another bov though. You'll need to also modify the reference port. Do a search there is an article in the newbie section about it. It doesn't sound like FIAV to me. When I had (self imposed) issues with my FIAV it just caused a high idle.

Try reading this if you'd like a way to test for your FIAV being bad.
http://www.dsmtuners.com/forums/151719045-post5.html
You can read the entire thread by clicking on the link in the upper right hand corner of that page. It is a worthwhile read.

 

[91-gsx]

You can mod the 2g bov by putting it in backwards. Really you should just switch to another bov though. You'll need to also modify the reference port. Do a search there is an article in the newbie section about it. It doesn't sound like FIAV to me. When I had (self imposed) issues with my FIAV it just caused a high idle.

Try reading this if you'd like a way to test for your FIAV being bad.
http://www.dsmtuners.com/forums/151719045-post5.html
You can read the entire thread by clicking on the link in the upper right hand corner of that page. It is a worthwhile read.

The FIAV can either get stuck open, or it can be stuck closed, or a variation of that. If yours is stuck open, then it will always idle too high. If it is stuck closed then it will idle to low.. The guy who made that write up was right, you can get to the knob that you turn, but I got there too and good luck turning it... I broke mine trying everything to get it to budge.