Issues after 16g install

[racingmason]

I installed a good working 16g with a fmic off a friends gst that he parted, as well as a 3inch exhaust and a hks manual boost controller. I am having a few issues. First the idle after it gets warm constantly revs from 1000 to 2000, no matter what i do to adjust the idle, secondly my boost vac gauge shows 10 in hq of vac at idle, and as i increase the throttle it increases up to 20 or more, when it should be building boost at 5000 rpm.

I have checked and rechecked the vaccum lines, and all the couplers are tight, on the piping as well. Also I have pulled the vac line off the waste gate to see if it builds more boost but, its still the same.

 

[GsXdSmKingGsX]

Have you done a leak down test yet? Just eying things wont do it.

 

[JStrateger]

Take a picture of your engine bay showing all the piping and how everything is ran, sounds like you have a boost leak.

Are you talking about the idle sits at 2k or does it bounce/surge around between 1k-2k? The plastic brown screw on the throttle body controls the idle.

 

[racingmason]

the idles jumps from 1000 to 2000 over and over, and adjusting the idle screw does nothing to it. I can take pics in the moring. I have the boost controller tapped of the vac line by the map sensor with a t, that goes to the BOV, and then to the MBC, And off the MBC to the wastegate. I have the MBC set to max boost and i see mabey 2 psi when i wot it to 6000 rpm in my garage.

 

[ktgurl87]

Nothing should be t'd off or into the BOV line. That line should dedicated only to the BOV.

 

[racingmason]

According to the VFAQ boost controller install, that is how the did it as well.

 

[williillii]

Well then that's wrong also. This probably isnt all of your problem but it sounds like you basically have everything T'd off one boost/vacuum source?

Should be like:

BOV nipple on intake mani goes to BOV.
Boost gauge you can use the "P" port on the throttle body.
Boost controller should have a nipple on the compressor housing of the turbo, the j-pipe, or the hotpipe close to the turbo.

After you fix that stuff then I would start with a boost leak test, make sure your wastegate actuator is working correctly, and then check for exhaust leaks.

 

[racingmason]

Ok thanks. The boost controller is on the P port. I didnt see a nipple on the 16 housing, so i just hooked it up like my friends had his with no issues. Also there are no exhaust leaks. Im going to build a boost leak tester today.

 

[LiquidX]

The exhaust leaks he's referring to would be any sort of leak pre turbine which could include and bad head to manifold gasket, missing bolt/s, crack in the exhaust manifold (some aren't even visable), bad turbo-to-manifold gasket, cracked/damaged flapper and/or seat, stuck-open flapper.

To back up what was said above, shorter the vacuum lines the better as it will be a quicker response and will become more accurate.

You need to also re adjust your BISS as you are most likely WAY out of spec now on the IAC. To do a "quick adjust" turn it all the way in and then back it out 4 full turns or so. Let it sit so the IAC can re adjust and then see how your idle is sitting. You only do small adjustments and let it sit so the stepper motor can adjust itself.

 

[90gen1tsi]

you wont build boost sitting in your garage... You need to drive it.

 

[JStrateger]

You need to also re adjust your BISS as you are most likely WAY out of spec now on the IAC. To do a "quick adjust" turn it all the way in and then back it out 4 full turns or so. Let it sit so the IAC can re adjust and then see how your idle is sitting. You only do small adjustments and let it sit so the stepper motor can adjust itself.

Something I do when adjusting my idle, which might not be correct, is ground the brown timing connector on the firewall first. This might not actually do anything relevant to setting the idle but it always seemed to help me and get rid of surging.

Doing this also got rid of my ISC Check Engine Light I was fighting with for so long (Which stayed on months even after I replaced the ISC), which may or may not have been a coincident.

It won't hurt to try it out I guess.

 

[racingmason]

i fixed the rampant idle. Someone forgot to top off the coolant. I still got a boost leak somewhere, as i have about 14 in/gh at idle, and builds up to 13psi with the mbc set to max, damn it pulls hard, but as soon as the bov kicks open it dies. and yes the bov is recirculated.