Just need to clarify a few things....

[techlogic89]

Ok first:
My BOV is leaking. Not just a little leak, its just openly letting air flow at idle.

Its one of these things....

APEXi Twin Chamber Blow Off Valve UNIVERSAL - ALL CARS

It was on the car when I got it.

This would cause a constant high idle right? It's idling a 1900-2200rpm and does these weird little 200-300 RPM hiccups sometimes, and sometimes when engaging the clutch or brakes.

Its weird though because it did not have this problem before I installed my "new" tb (it was a rebuilt one) yesterday. The idle was crappy before, but somewhat controlable, and WAS stable at idle at ~700-900rpm. It used to just stall out if you didnt catch the RPMs while decelerating/shifting.

The ISC has been tested and is good, the car has NO method of tuning on it so idk how to set the TPS.

Second:
All the vaccum nipples were capped when I got the car so I just recapped when I reinstalled TB. It's a '90 model. Anyone know the proper hook ups or know of a diagram.


If it matters I also just relocated my battery to the trunk yesterday as well.

TLDR:

I know I cant really do much until the massive boost leak is fixed, it's just that I don't understand how installing a different (same year) TB could mess everything up. Like I said the idle wasn't great, but managable before the tb install/battery relocation.

Thanks

Oh, and I wanted to ask if its ok to hook up a MBC by teeing into the bov line, and other side into WGA. I've gotten mixed results in search.

 

[joescool2008]

I would hook up the Boost controller like that, and maybe the TB shaft seals were worn and leaking causing your issue.

 

[techlogic89]

Yea that would be a good possibility, but the TB I just put on was totally rebuilt, sandblasted, all seals everything.

 

[miguelmcv]

Here is the diagram for the vacuum hoses.


http://www.dsmtuners.com/forums/art...-speed-shop-vacuum-diagram-removal-1g-2g.html

 

[WeaselHack]

Its normal for a properly configured BOV to be slightly open at idle. Im confused because your profile says you have a N/T?!?! Speaking of profile, please fill out your mod list so people can better help you.

If you are running stock engine management then you need to have the BOV re-circulated. Cant really go any further without more details on your setup.

 

[BIRDCLAWTSi]

First off, Dont tee the BOV line into anything. Keep it seperated, As for the MBC, Keep it seprate as well. You shoul have a nipple on the turbo, Or the turbo outlet, If not then You should find a way to make it happen. The MBC and BOV both need to have a clean vacuum/pressure source. On the Boost controller,The shorter the vacuum line the better.

The boost/vacuum leak you are experiencing after the throttle body swap is either the tb shaft seals, tb gasket, or a port not blocked off. boost leak test it and spray soapy water around the tb. Only other thing is, Is the bov recirculated? The picture of the BOV does not look recirculateable(If thats a word?)

 

[techlogic89]

Oh right sorry, I had a '97 RS before the '90 tsi. Ill Update my profile.


And yes, the BOV is unrecirculateable . Thats part of my problem. I am waiting on the chinabay one coming with the PR fmic kit, until I can afford a quality piece.

I'll recheck all bolts, seals and ports, but that idle just wont budge lower than 1900, cold or warm dosen't matter.

I realize the setup is kind of jacked up, I am trying to correct the issues one at a time, but I am learning as I go.

Quick mod list: Evo3 16g, 3" truboback exhaust. Janky ebay fmic/piping. wally 190lph

 

[techlogic89]

Another symptom is when I engine brake/downshift its not smooth, kind of choppy at certain RPMs.

Does that help?

 

[aPOS]

First off, Dont tee the BOV line into anything. Keep it seperated, As for the MBC, Keep it seprate as well. You shoul have a nipple on the turbo, Or the turbo outlet, If not then You should find a way to make it happen. The MBC and BOV both need to have a clean vacuum/pressure source. On the Boost controller,The shorter the vacuum line the better.

The boost/vacuum leak you are experiencing after the throttle body swap is either the tb shaft seals, tb gasket, or a port not blocked off. boost leak test it and spray soapy water around the tb. Only other thing is, Is the bov recirculated? The picture of the BOV does not look recirculateable(If thats a word?)

You have not mentioned whether you used this advice. If you have not changed the connections, or done a BLT, as described by birdclawtsi, then your symptoms will continue being what you are experiencing.