2G Low idle

Turboed_talon_tsi · Jan 17, 2023

Hello, I just finished my punishment racing/cx racing kit and everything seemed to be fine. When I took it out for a test drive it was acting weird, when I pushed the clutch in it dropped to 0-100rpms and stalled out. All my gauges were fine and the car ran really good after I got the rpm’s up. I’m new to cars and don’t know what to do. It’s obviously something to do with the ic kit and was looking for answers thanks!

99dsmer4g63 · Jan 17, 2023

First I’ll ask if you are still recirculating your blow off valve back to the turbo snorkel.

Secondly I’d assume you have a vacuum leak in something you did. Check all your connections and your vacuum hoses you may have taken off and forgot to re install.

Or just perform a boost leak test and I’m sure you’ll find something.

-Daniel

Turboed_talon_tsi · Jan 17, 2023

99dsmer4g63 said:
First I’ll ask if you are still recirculating your blow off valve back to the turbo snorkel.

Secondly I’d assume you have a vacuum leak in something you did. Check all your connections and your vacuum hoses you may have taken off and forgot to re install.

Or just perform a boost leak test and I’m sure you’ll find something.

-Daniel

Thanks, but I’m sorry, I’m still lost new to this.

When I looked and felt for leaks I couldn’t find any, all the hoses I took off I put back on I believe. I had a blitz BOV on before this.

My question is what does recirculating your BOV back to the snorkel mean. My vacuum hose goes to the throttle body which measures when to open up the BOV when I passed my desired boost correct?

The other hose is connected to my boost controller and IC piping in the second picture.

I attached pictures below and think I put every thing back how it was. Also my idle issue video

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steve · Jan 17, 2023

Let's see your MAF and the piping from it to the turbo.

The BOV opens when the pressure in the intake manifold it lower than the pressure in the IC piping. That usually happens when you have been making boost and you close the throttle butterfly. The point of the BOV is to release that pressure wave in the IC piping so it doesn't bounce off the closed throttle and smash against the turbocharger outlet.

The problem with venting to the atmosphere is all the air was measured by the MAF and the ECU is going to provide fuel for air that is no longer in the intake. So you want to keep it but route it in front of the turbo.

99dsmer4g63 · Jan 17, 2023

The front of the blow off valve. There is about a 1.5 inch opening facing the front of the car. There is supposed to be a hose connecting it to the pipe that is between the air filter and the turbo (the snorkel).

I'm assuming your car is running the factory ECU. The car will idle different and like to shut off between shifts and when pushing the clutch in without the blow off valve recirculating it’s discharge back to the turbo.

Search boost leak test on here and perform one on your car as well. Feeling around with your hand is not effective.

-Daniel

Turboed_talon_tsi · Jan 17, 2023

steve said:
Let's see your MAF and the piping from it to the turbo.

The BOV opens when the pressure in the intake manifold it lower than the pressure in the IC piping. That usually happens when you have been making boost and you close the throttle butterfly. The point of the BOV is to release that pressure wave in the IC piping so it doesn't bounce off the closed throttle and smash against the turbocharger outlet.

The problem with venting to the atmosphere is all the air was measured by the MAF and the ECU is going to provide fuel for air that is no longer in the intake. So you want to keep it but route it in front of the turbo.

I don’t have piping between my BOV and the snorkel. It should be the yellow cap that is scribbled off correct? My old BOV which was a Blitz didn’t have a connection and was just dumped into the atmosphere and ran fine, which is why I was confused but now understand. Thank you all for the help (pic below sorry for the quality)

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pauleyman · Jan 17, 2023

Turboed_talon_tsi said:
When I looked and felt for leaks I couldn’t find any, all the hoses I took off I put back on I believe. I had a blitz BOV on before this.

My question is what does recirculating your BOV back to the snorkel mean. My vacuum hose goes to the throttle body which measures when to open up the BOV when I passed my desired boost correct?

No. That is not how a BOV works.
Boost is controlled by the wastegate on the turbine side of the turbo.

chrysler kid · Jan 17, 2023

Can we see an actual picture of your engine bay? You have the valve cover breather hooked to a random filter behind the fuse box, its suppose to be plugged into the intake where the blow off valve goes into

Turboed_talon_tsi · Jan 17, 2023

chrysler kid said:
Can we see an actual picture of your engine bay? You have the valve cover breather hooked to a random filter behind the fuse box, its suppose to be plugged into the intake where the blow off valve goes into

Is there anyway to run it so it goes into atmosphere and fix my idling issues?

My old Blitz BOV was vented atmosphere and there was zero issues. I want to hear the pshhh BOV sound more and would highly prefer atmosphere but if I can’t, I can’t.

Is it 100% my BOV that is causing the idle issue if my old BOV was atmosphere as well? Thanks

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pauleyman · Jan 18, 2023

Turboed_talon_tsi said:
IMy old Blitz BOV was vented atmosphere and there was zero issues. I want to hear the pshhh BOV sound more and would highly prefer atmosphere but if I can’t, I can’t.

Wanting the pssshh sound at the expense of a properly running car is the contrary to going fast. Which is it you want? You cannot tune around it.

Please update your profile so we know what you have. If you have an intercooler and 16g and no tuning solution you are walking a path to destruction. Fuel mods? Wideband? What else does the car have?

ryan4269 · Jan 18, 2023

Having same problem, though I know for a fact I have a significant amount of boost leaking past the PCV, I’m going to end up putting a check valve between the PCV and IM.

I highly suggest you do a boost leak test (search on YouTube, many tutorials and methods) because nobody can tell you if you do have a vacuum/boost leak or not over the internet.

If you had no problem venting to atmosphere with your previous BOV then it should be sensible that blowing off to atmosphere is not an issue in your circumstance.

BTW that BOV is a fake. I seriously bet that the BOV itself isn’t sealing and IS your whole problem here. If you lack the tools to do a boost leak, you could take your BOV off and block off/seal the flange. Then go test drive and see if your problem persists + get some stu stu stu.

Maybe I’m wrong? If someone wants to chime in, it wouldn’t be recirculating without a BOV, but it also wouldn’t really be blowing that air away

99dsmer4g63 · Jan 18, 2023

My opinion the only way to properly run a vented blow off valve is to run speed density. You don’t think I wanted to hear pshh noises the first 8 years I owned my car? Because I did LOL

. Not at the expense of my car not running 100%.

I agree with Ryan that the “new” blow off valve is the problem. It is not sealing correctly and is causing a massive vacuum leak.

Put your old Blitz one back on if you didn’t have any issues running that one atmospheric.

FYI most wisemen on here are old school. None of them are gonna steer you into venting the blow off valve is okay without properly doing it.

Paul is also correct. If your car has no fuel upgrades, a way to control fuel flow and a 16g with a MBC. Your car is a ticking time bomb.

And your car is never going to run properly with the blow off valve atmospheric. Just because your car runs okay that way doesn’t mean it actually is. You can watch the wideband every time the blow off hits and see the problems it causes to the air fuel ratio.

-Daniel

Turboed_talon_tsi · Jan 18, 2023

99dsmer4g63 said:
My opinion the only way to properly run a vented blow off valve is to run speed density. You don’t think I wanted to hear pshh noises the first 8 years I owned my car? Because I did . Not at the expense of my car not running 100%.

I agree with Ryan that the “new” blow off valve is the problem. It is not sealing correctly and is causing a massive vacuum leak.

Put your old blitz one back on if you didn’t have any issues running that one atomospheric.

FYI most wisemen on here are old school. None of them are gonna steer you into venting the blow off valve is okay without properly doing it.

Paul is also correct. If your car has no fuel upgrades, a way to control fuel flow and a 16g with a MBC. Your car is a ticking time bomb.

And your car is never going to run properly with the blow off valve atmospheric. Just because your car runs okay that way doesn’t mean it actually is. You can watch the wideband every time the blow off hits and see the problems it causes to the air fuel ratio.

-Daniel

Thanks for the help Daniel, gonna do a boost leak test and try both BOVs after I get home.

steve · Mar 5, 2024

When it comes to idling, the issue is does the BOV leak air into the engine under vacuum? It shouldn't. Perhaps your old one wasn't leaking.

Same thing for the vent on the valve cover. It needs to be connected to the intake pipe after the MAF. Under vacuum when the PCV is open it just provides another path for unmetered air to enter just like a leaking BOV. Under boost you want the crankcase under vacuum and the turbo creates some in the intake tube. If you pushing oil into those paper filters they tend to block up.

The main issue with venting the BOV to atmosphere is what they then do to your AFR's when they dump all the air that's been measured and accounted for out of the system with burning it. The ECU still thinks it's there and injects fuel based on that.

SD doesn't actually count air mass, it guesses based on current temp, manifold absolute pressure, and the VE. So it doesn't have this issue with leaks and lost air.

If I misspoke someone will come along and school me...

chrysler kid · Mar 6, 2024

if you are the original poster of this thread it looks like you forgot to put a gasket under the throttle body connection to the intercooler pipe. the factory gasket was a stamped steel and I should be able to see it in your pictures but its not there

perform a boost leak test

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