Car dies when the BOV is blocked off
 

Ok so I have a new one that is completely odd.

I have a Boash BOV in a VTA setup. Car run fine like this. Then it die(read my other post). Well got the car idling fine but the bov is blowing air out(yes I said it is blowing air out) at idle. If I put my hand over the bov and seal the leak, the car dies. If I unhook the vaccum line of the BOV and seal up the new hole the car dies.

I can have the car in netural and rev the motor fine, as long as the leaking BOV is hooked up right.

WTF is going on?? I am about to pick up a known working BOV to fix that.

noted information:

stock 1.6 ECU
1.8 motor
1.6 TB
still have the shitty AFM(stock 1.6)

The car ran fine until it died on the road. The only I did to fix my other problem was removing the VC to algin the CAS easier.

Any help would be great cause I am lost.

see the screw on the TB? turn it counter-clockwise a bunch of rotations, try again.

I'm somewhat confused. There wouldn't be any boost at idle, so you would only feel vacuum at idle through the BOV. As posted, I would check your idle setting, but this is what would be happening to your car right now: Your AFM box will be metering the amount of air it sees, and since air is also coming in at your blow off valve, your car would be running leaner then it should (more air then fuel). By blocking off that BOV, your car should see the proper air/fuel mixture, and should run better.

sorry to tell this isn't my first boosted car and yes the BOV is blowing air. I have even confirmed it with a piece of paper.

I also tried adjusting the Idle air valve screw like you said Brain. If I open the valve all the way and then cover/removed vaccum of the BOV the car barely ran and ran like shit. Popping often and idling like shit.

i am 100% at a lose here

you're running super rich. dunno why. this a new issue? change anything?

I have change nothing. The car was running good before the CAS. It was running a little rough, kind more of an high idle and running rich but once load was applied to the motor the car smoothed out. Now if I try to add load to the motor the car just bogs down.

The only other thing I can think of that would cause that situation is a messed up AFM.

Well I have tried unhooking the AFM and the car dies

Also if I push the flap door open without adjusting the TB and car started to die.

This made Eric and I both think that it kinda of sign as the AFM is still working.

I didn't think the stock ECU would let the car run right if you were VTA anyway.

Did you try routing the blowoff back into the intake tract behind the afm so that at least all of the air gets metered?

Well... I know the stock ECUs don't like VTA... the weird thing is that the car has been running for about a month now in VTA with out any major issues. Granted until now the BOV didn't leak at idle. I have a Greddy RS next to me that should seal at idle. I need a bigger hose so I can try it.

First you have to get rid of the AFM to VTA till then you have to recirculate or is bound to screw up your idle, and air/fuel ratio...and yeah it looks it's also leaking A lot!!

ok yea I know VTA with an AFM is not the correct way and has it issues... but 1) the car been like that for over a month no real issues.

2) even if I remove the BOV signal, closing the BOV the car dies so the BOV being VTA doesn't explain why when it's not leaking the car dies..

Explain why the big "hole" in my intake system is an out instead of a nomal in and why when that "hole" is sealed the car instanely dies.

What vac line source are you running to the BOV? Did you forget to hook the vac line back up to your FPR and what vac line source are you using for your fpr?

I have a single line running from the IM to the BOV. Also a single source from IM to Boost Gauge. My FMU and FPR is source together of the back of the manifold. Everything is hooked up, and just like it was before the car dieing.

I have double check to make sure I didn't change since before my CAS backing out.

Unplugging the AFM will kill the car right away, because it turns the fuel pump on and off. You can jumper the fuel pump to stay on through the diagnostic box, but I would still think your AFM is reading improperly.

if the car is running and you unplug the AFM it should still idle, since the vacuum is pulling the flapper open, the fuel pump stays grounded. You should also be able to start the car with the AFM unplugged, but you cannot rev the motor.

Not if you unplug the electrical connector, because the flapper is jumpering two wires on that connector.

you make a valid point. all i know is I was able to do it. i could idle the car, then i couldn't rev it, then i looked down and said oh yeah, plugged it back in and i was off.

Is it possible that he is running too lean? Since he is losing metered air out the BOV it makes the car run richer. When he plugs off the leak it runs leaner and dies.

^ was what I was thinking. No WBO2 I take it either to find out.

ok I so i got the car to idle the the BOV sealed up. It idling stupid rought. Like at 600 rpm rough.

The thing is now my vaccum is only about 4in vs when leaking though the BOV of 15. I am in the middle of building a vaccum leak testers right now.

i can confirm this, i did it yesterday.

OK so after having Doppleganger come over and bouncing ideas around I think I finally figured out what the f**k is going on.

Oh yea welcome to once in a blue moon :D

So after playing with a few things Mike figured out the turbo seemed to me sucking in more air. Well so we tested the theory with his car and so be it. So we figured out that my car is starting to build pressure at idle. So this makes no sense cause I never seen a car start building pressure at idle ever. Well after playing with the car more, leaking the BOV, playing with the FPR we notice that if I remove air from entering the intake manifold or increase the fuel pressure the amount of suckage from the turbo decreased.

So after thinking things about, I have a theory that seems to make sense and only I would have this problem lol. Ok so I am running a stupid small turbo. Well the car is leaning out a idle(which I knew I was a little lean originally but not this bad) causing my EGTs to increase. This increase of EGT is causing the exhaust gases to increase their speed over the turbo. Those spooling the turbo more at idle then a normally. This is why my BOV was blowing air out instead of sucking like normal. Also explains why my vaccum is so messed up.

After talking to Ben91, we agreed that if anything(for a quick style fix) I should adjust my AFM to richen the car up. So the plan over the weekend is to pick up a narrow band gauge(since I can then reuse the gauge for when I finally get a WB) to test if the car is just stupid lean and then to adjust the AFM to richen the car up.

Thanks to everyone for all the ideas and to the people that talked about the car leaning out cause that made me think of how leaning a car will increase spool ever so much.

That's ridiculous! What size of turbo do you have?

Why do people think they can turbo their cars without a damn wideband?

Cause the **** government won't give me my money and I lost my second job right in the middle of building my 1.8 and my 1.6 started to die. So I did a low boost build until I can get WB and MS. Not the way I would like to do it, trust me.

Tiny... I have the spec on my build. It is as small or smaller then a DSM t-25. If I been told right, it is Savington's old T25