webrest

Hi all,
Today I photographed and sketched a diagram from a friends car for the vacuum side of the cruise control installation that I needed to know for the retro fit that I am performing on my own car.
I reside in Australia but my friends car is a Japanese import into our country [beautiful low mileage car I might add] but it seems to have a very complicated vacuum system for the cruise control and brake servo.
My question is whether or not it needs to be so complex. I have attached the sketch I made so you will have a better idea of what I am getting at.
I would prefer to place a 'T' piece in the Vacuum line that is going to the brake servo and be done with it without the rest of all the gear [which I might add is not shown in the parts manuals]. My fear is that if I do it this way it will upset the sensing side of the computer. The only reason that I can come up with for this extra plumbing is that it may there to establish some sort of damping system in the vacuum line so that it doesn't upset the management system. It may however be just some sort crazy requirement by Japan.
I would really prefer not to include the extra parts as I can't find even find them in the parts manual let alone have to shell out for them at the Porsche dealer.
Any advice would be much appreciated but I realize that this a bit off the beaten track and it is not something that would readily be on the tip of everyone's tongue but heres hoping somebody out there may have noticed how their car is plumbed when pulling an engine or even replacing one of those rubber hoses. Here's hoping.
Thanks Dave[IMG]Porsche 911_Cruise control_Vacum Diagram 001[/IMG]

webrest

Sketch didn't upload not very helpful for you all is it?
OK I will have to see if I can rectify the problem
R. Dave

webrest

Fingers crossed!!!

Ed Hughes

You look to be pretty close to what the factory does. I'm not sure on the tapping into the brake line, but I can look. I've got CC and can snap a couple of pics. They'll have to be on my phone for now....I left a Canon G10 at a jobsite the other day-remembered it 10 minutes after leaving and it was gone. Got a new compact from Amazon coming in this week.

I've taken every luxury but CC off of Ruby. Except my cable just broke, which is NLA.

AJ88CAB

I belive all that plumbing contains some check valves that allows the brake booster and CC to use manifold vaccum without a sudden loss of brake boost, keeps the CC regulation constant, AND keeps the engine running correctly. I would be cautious about removing any of it. The factory "generally" has a good reason for doing things the way they do...although it is not always apparent to us mere mortals

Ed Hughes

Andrew is correct-I can picture it now. You are schematically correct in that the stock setup does tee off the line going to the brake. There is a check valve, IIRC. That manifold is a Porsche part that maybe was $100 or 120 when I replaced it 3 or 4 years ago. Probably worth its weight in gold and safety.

webrest

Thanks fellas,
I was afraid of everything you said, looks like there is no easy way out.
Andrew you are perfectly correct the factories never do anything without a reason.
As far as removing the parts I don't have any to remove as this is a retro fit and it is fighting me all the way
On a closer look at the fitting I note that has a black end as well and that uses suggests that it a one way valve as PCV valves sometimes do.
OK so now what to do, it looks as though there is no way out of it. I will have to reproduce the plumbing. The problem is I cannot find the parts in the parts manual. If anybody has some that they would like to sell please contact me and I can pay for the bits thru. Paypal.
Once again thanks to Andrew and Ed for your help so far.
R. Dave

rusnak

I can post the parts numbers and the factory exploded parts diagrams. But I think the best advice would be do buy everything including the all important brain and the no longer available throttle cable from a used parts distributor. Get all the hardware that way in one shot. Don't forget the steering column switch too.

There is a good troubleshooting procedure in the Bentley 911SC manual. My Carrera manual did not have it, but I have an early edition manual.

webrest

Hi Rusnak,
Please post the parts number diagrams if you do have them.
I need the part numbers for the items marked #2, #4, #6 and the part marked "copper pipe" on the Vacuum Dia. sketch that I have posted earlier in the trail.

I have the parts already for the main installation in fact they are all in place already this is the last remaining part of the project that needs to be addressed and like the rest of the job it is fighting me all the way.
The parts manual I have only shows the cruise control components but not the vacuum loop that stabilizes vacuum. So they are the numbers I am after.
R. Dave

rusnak

I think I got the "Tempomat", but on second look, I don't have #4. I have to go back and look some more.

The copper pipe is still available from Porsche. I bought one last year.

rusnak

Argh! It's confusing because the direction of the copper pipe changes from sometime around '85 '86 maybe? I think I have the parts pictured, they just look a little different from the ones illustrated.

Ed Hughes

Mine actually looks a bit different than that trombone-shaped bit. I finally found a good pic:

rusnak

Ed, yours must be an '84? I think the direction changed the next year, or in '86. I'll look again.

BTW: do you have your headers de-blued? Gosh, that is a clean motor.

webrest

Thanks very much for your assistance fellas I have them on order from the dealer here in Melbourne and they are getting them in from Germany. They are guessing that they will be here by the end of the week.
Not bad service really and strangely enough the four parts that I purchased were fairly inexpensive. The copper pipe section I will take care of myself. That one was a bit heavy.
My '85 also has the longer copper pipe and I assumed that it was because my car never had CC and that was how they came.
+1 on the motor to Ed it looks sensational.
And Rusnak thanks very much for the diagrams now I know what I need it was there in front of me all the time just didn't know where to look. Thank the giant head that you guys were on the ball
All the best Dave

Ed Hughes

Indeed it is the motor of my '84. It darn well have better be clean as that was the end of my assembly. It will be interesting to see how it looks when I drop it soon for the new goodies.