[Aqid]

Quick question: what is the hard plastic line that runs in front and around the intake?

About halfway through there is a T splitter in it, and the nipple on the bottom side broke off on mine. Seems to have been like that forever, but I'm tracing the dreaded 30FF and wonder how that ties into everything. What does the hard plastic line do, and what does the rubber one do that T'ed into it? The rubber line on mine seemed to have disappeared so just asking for some extra information so I know what I'm doing.

Edit: Marked it on a picture to make the description a little clearer.

Thanks in advance!

[Emilime75]

Vacuum. If I recall, the hard line goes between the vac pump and brake booster. Can't remember where the rubber goes after the TEE. If any of that is disconnected, you'd have several issues, including a very hard brake pedal.

[BSM n54iS]

^

I just purchased the ECS relocation kit for this too, hopefully it fits up fine.

[Aqid]

I glued a new nipple on it and reconnected the rubber one that's TEE'd in. Everything seems to work, the 30FF was something different though. Had some DV issues. Still not entirely sure what the rubber hose goes to, tried to follow it but its sleeved together with other things. Either way, I'm glad it's running 18 psi again lol.

[relative4]

Rubber hose goes to exhaust flap and I think one other thing?
Any break in that vacuum system can/will cause 30FF due to loss of wastegate control.

[Emilime75]

Originally Posted by Aqid

...Had some DV issues...

DVs are vacuum controlled.

[Aqid]

Originally Posted by Emilime75

DVs are vacuum controlled.

Yep that's exactly what happened. I saw that rubber hose that's supposed to be tee'd in and accidentally connected it to the DV Y splitter after having my charge pipe out, so that's what caused the 30FF. Reconnected the vacuum from the intake manifold to the DV Y splitter and everything is fine now. Weirdly enough with or without the rubber hose tee'd into the hard plastic line doesn't seem to make a difference. I assume it's there for a reason so I did fix it, but I got curious and wanted to see if anyone knew what it lead to.

[Aqid]

The small line that tee's off controls the the exhaust flap. I've disconnected mine and just have a vacuum cap on the tee.

Found this on another forum. Makes sense that it didn't do anything because I have the exhaust flaps open.

For anybody searching, the answer was: Hard plastic line is brake booster line, rubber tee'd off hose is exhaust flap vacuum line.

Thanks everybody!

[relative4]

Originally Posted by Emilime75

DVs are vacuum controlled.

Just to clarify for anyone learning these systems, the DVs are controlled by intake manifold vacuum, because it spikes when closing the throttle. Wastegate control, brake boost, and exhaust flap control vacuum come from the vacuum pump, which provides a theoretically constant vacuum.