[sciroccosven]

My scirocco started running like absolute crap last fall early winter. I just thought it was cold weather + old tune up and sat it. I don't drive it in the winter anyway as our local municipalities have the roads coated in salt all winter.
Fast forward. I changed plugs which are gap around 33, new cap, new rotor. I left the wires on since they didn't look bad. I doubt that is my problem but I will hit them with a multimeter to confirm their status.
I had some loose ends as far as my vacuum lines go. I decided to just remove my charcoal canister and I plugged up all lines that were associated with it. My vacuum issue is right before the throttle body. Where do both lines go? I have one plugged but the second went to a light purple hard plastic line that was a dead end near my fender. Not sure what happened but it is slashed so I plugged that line as well.
My car is running in a manner that it could have a vacuum leak and I am trying to figure out where these two line lead. Are they necessary if they are capped off?
I also have found an opening in the top of the upper airbox as shown in the pictures. This has to be a vacuum leak but I am not sure where it goes. I would have to assume that the it goes back to the intake tube but I really don't know.
Here is the picture of the intake tube. I have both blocked off for now but I am pretty sure one of the lines should still be active. Just not sure where.

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Here is the mystery line that WAS on the intake boot right in front of the throttle body

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Last but not least hole on top of the airbox. I have the purple vacuum line pointing at the hole.

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Some help would be greatly appreciated.

 

[scirocco16vobsessed]

Re: Scirocco 16v (factory) Vacuum questions (sciroccosven)

The purple line goes to a vacuum container, sort of a storage tank for vacuum pressure that's located in the fender. It feeds vacuum powered mechanisms like your heater damper. The other feeds your knock sensor module and is vital to engine function. This is probably where youe engine issues are coming from. Replace the vacuum hose with silicone hose from your local auto parts store. The knock sensor module is underneath the rain tray, on the driver side. The vacuum port is on the side of the module, and the module will say Jetronic on the side of it. Change out as much of the old cloth covered lines as possible, following the existing and replacing as you go.
The knock sensor connection is the only vital connection for engine performance. Start here for your engine issues.

 

[sciroccosven]

Re: Scirocco 16v (scirocco16vobsessed)

OK, I removed the charcoal container system and plugged off corresponding lines so that isn't a big deal anymore in regards to the purple line.
I will have to take a look at my Jetronic box. I checked it out today and it looked in good shape. I will take it out and see if there is a second line. Yeah your right, it is time to get a couple yards of vacuum line and replace everything. Something I have always wanted to do but never took the time.
There is a cluster of vacuum lines above the header, is it possible that the jetronic box is hooked into that or does it have to be directly to the intake tube vacuum port? I thought I followed the line to the ecu and it looked like it was hooked into the vacuum system.
Thanks for the help. Any clue about the hole on top of the airbox on the cis system?


Modified by sciroccosven at 7:14 PM 3-19-2010

 

[Rannoch]

FV-QR

that hole is just for adjustment of the CIS fuel mixture

 

[scirocco16vobsessed]

Re: Scirocco 16v (sciroccosven)

Run a dedicated line from manifold connection to knock sensor module. The rest can connect to the second manifold port. Use some 1/4" barbed tees to connect multiple lines.

 

[sciroccosven]

Re: FV-QR (Rannoch)

Quote, originally posted by Rannoch »

that hole is just for adjustment of the CIS fuel mixture

There doesn't appear to be anything to adjust inside. Its just a wide open hole that appears to go through. Did something work its way out?

 

[sciroccosven]

Re: Scirocco 16v (scirocco16vobsessed)

Quote, originally posted by scirocco16vobsessed »

Run a dedicated line from manifold connection to knock sensor module. The rest can connect to the second manifold port. Use some 1/4" barbed tees to connect multiple lines.

OK, I will. On the basic vacuum diagram on the hood it appears to be set-up properly. There is a larger vacuum line that goes to the brake booster. The vacuum line is run from that booster line to the yellow jetronic box. Is this the best way to run it? I can reroute and plug when I replace vacuum lines if there is a better place to run it.

 

[sciroccosven]

Re: Scirocco 16v (sciroccosven)

up

 

[prom king]

Where does the vac line coming from the passenger side, floor, connect to?
Looks like it's coming from the Fuel tank?

 

[CodeMan]

It goes to the charcoal canister. It's not a vacuum line, it carries fuel vapors from the tank to the canister.

 

[dkfackler]

Quote, originally posted by Rannoch »

that hole is just for adjustment of the CIS fuel mixture

There doesn't appear to be anything to adjust inside. Its just a wide open hole that appears to go through. Did something work its way out?

There is a 3mm Allen screw under that hole, used for adjusting the idle mixture(CO%). There was a 'tamper-proof plug' in there initially, but it's been removed(and not replaced) during a previous tuneup. You can safely ignore it-- just leave it open. If it bothers you, put a strip of aluminum duct tape over it. Any air entering there will go through the mixture control and throttle properly-- it's not a vac leak.

 

[shortwave360]

Danke! bookmarked

 

[dkfackler]

Danke! bookmarked

Bitte!

 

[austin neuschafer]

oxygen sensor age???