JasonAndreas

Does anyone know what is controlled by the easy to accidentally turn **** on the vacuum solenoid? In the picture it is dead center and black. I've checked Adrian's book, the technical workshop manuals and Probst's book and I can't find anything describing it.

Jeff Curtis

DON'T TOUCH THAT!!!

...just kidding, actually I'm not sure I've run into that little device before...almost wondering if it's on all of our 964s or if it's for say Tiptronic or Euro models?? ...again, I dunno.

Excuse my ignorance, but WHERE is Berkshires?? Do you have a US or Euro, even Swiss model??

Adrian

I am with Jeff on this one, I have seen many 964s and I have never seen that puppy before. I think the **** is possibly a reset switch or activation indicator but I have no idea what it is for.
Ciao,
Adrian
964C4

Jeff Curtis

I'm not so sure that's an adjustment ****...rather, it looks to be a vacuum port block or some device that provides resistance (rather than being wide open) as there appears to be a vacuum line attached to the unit.

Okay, looking at the pic once again, I am now oriented to it's position. I see the ISV in the backround and the rubber boot intake clamps down low.

We're at the very top of the FI unit, you probably have the engine lowered a bit?? ...either that or you're double-jointed/have a nifty digital camera?

There is a manufacturer's name and probably a PN but it's not readable from the pic - curious as to what this is...and if I have one!??

Adrian

I would be interested to know where the plug goes. Them three pins must do something. Maybe an aircon compressor at idle "off" switch?
Ciao,
Adrian
964C4

mojorizing

Hi Jason,
I got one of those! It's part of the emissions control system, it looks like. That solenoid is right on top of the engine , and according to my vacuum hose layout, actuates the "tank vent valve" indirectly via manifold vacuum. There is a connection to the canister also.

Sometimes a **** is just a ****, and in this case I think this one is less than that. I goofed with mine, and it appears that it could be at most a cap over another vacuum port of that solenoid. That solenoid has a 2 wire harness connected to it, the third post being a plastic locator pin.

Good question, and let us know if you find anything more on this here puppy.

Kevin

Adrian

Dear Kevin,
You are correct that is the tank vent valve I think you will find. It is part of the carbon cannister emissions system. Everyone of our 964s have one.
My mind must be elsewhere. This valve is opened to vent excess fuel vapours into the carbon cannister on start up. It is electrically monitored and tested by the DME.
Ciao,
Adrian
964C4

ian c - u.k

i just fitted a new one of these !!!!
it fits with 2 screws to plastic intake manifold .
it is a vacume valve .
it is not a **** , it just covers a hole !!

JasonAndreas

I'm 3 1/2 hours west of Boston, Massachusetts and I have an 1993 RS-A.

The solenoid with the easy to accidentally turn control **** is item #22 in the following diagram, the check valve that connects to the carbon canister is #33.



There are two vacuum hoses running off the solenoid, 1 goes directly to the motor that opens the resonance intake flap and the other hose has a t-fitting that has one hose going to the vacuum reservoir under the airbox and another hose running to the check valve that connects back to the intake manifold crossover. IF you turn the **** you can feel some tension so it at least feels like something is being adjusted (or there is dirt behind the ****).

I've searched around online but I haven't found anything on the solenoid, the writing on it says;

PIERBURG
W-Germany
7. 21339.13 12V
2 065

Jeff Curtis

I checked it out last night, it's a block-off for a vacuum port. It's possible this block-off would be removed to hook up a gauge/diagnostic device??

FWIW, I turned it, and turned it...SEVERAL times...then went for a test drive - OH MY GOD!! ...the POWER!!

William Miller

I'm doing a 3.6 conversion so I'm searching and studying everything I can find about the vacuum lines. This is the 1st thread I've come across on this device. I was playing with it a bit last night. It doesn't feel like an adjustment or a vacuum cap because its too loose. I was thinking that it could be a push (test) button to open the valve and actuate the flap. I can't test because the engine is still on the stand.

BTW or while on the subject:
I'm wondering what vacuum lines are still needed for my swop into an 81. I don't need emissions so I was thinking of deleting the valves etc. for the carbon canister. (mine's different anyway.)

I was also scratching my head about the complicated (or sophistocated) vacuum line setup for the power brakes. (Is this needed for some reason because of ABS? or maybe because of the resonance tubes?) Can I just run a hose to the connection on the back of the left intake manifold?

Red rooster

Its a blanking cap ! Some VAG group cars use the other end when the cap is off.
That little sucker is used for all sorts of vacuum switching jobs .

Geoff

William Miller

You sure?
I guess I better figure out why my cap seems so loose!
So is vacuum present there all the time or only when the selenoid opens it?

Thanks Geoffery!