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Posted by: type4org Jul 27 2006, 07:55 AM

I'm currently in the process of replacing all the vacuum hoses on my '76, but all the vacuum diagrams I can find are at least slightly off or miss stuff. Mine is a CA model with all the goodies (EGR, air pump, catalytic converter). Does anyone have a suitable vacuum diagram?

One thing I noticed is that the EGR valve is not connected to anything and I cannot find an open nipple for its vacuum line, which is still connected to the EGR valve, on the throttle body. However, the distributor advance is connected to a nipple in the correct vicinity, which, according to one diagram I have, is simply not connected on many 74+ cars.

My symptoms right now are that the car wants to die badly when started and hesitates/bucks when I'm not careful during warmup.

Any help greatly appreciated

Posted by: Bleyseng Jul 27 2006, 08:05 AM

take some pics of the engine and smog stuff. I have never seen in person a complete setup as its usually been hacked or removed.

The vacuum advance should be going to no where. The vac retard is what should be hooked up. This is the lower slightly larger hose on the vac can.

Posted by: type4org Jul 27 2006, 08:10 AM

I'll try to take some pictures tonight if I don't forget it. The setup is indeed complete (I bought the car less than a month ago and it had 24,500 miles then), but might have been in the hands of less-than-competent mechanics.

The vacuum retard is hooked up, that one winds around to the opposite side of the throttle body.

Posted by: Dave_Darling Jul 27 2006, 10:04 AM

I think the ported vacuum fitting (advance fitting) on the throttle body runs the EGR. In at least some cases the line has a T that also goes to the distributor.

Check the 75 1.8 diagram on Pelican's site for some of the details of how smog equipment gets hooked up...

--DD

Posted by: AZ914 Jul 27 2006, 10:30 AM

I have a 75 2.0 with all the smog crap still hooked up. I will do my best to remember to snap some pictures of that spagetti tonight.

Posted by: type4org Jul 29 2006, 02:15 PM

Today I went and replaced all the vacuum lines that I could, going off a kit purchased from an unnamed but well-known vendor (No worries, Dave, not Pelican!).

The good:

- The hoses that did fit were all cut with a couple inches to spare, no problem with the lengths.

The bad:

- The kit was advertised as fitting '75 and '76 cars, but did not contain any hose for the connections to and from the charcoal canister. Looking at what's left over (a bunch of 14mm ID hoses) they seemed to assume that 14 mm ID is correct, while in reality it is 12. I could have made it work with hose clamps, but the kit did not contain any.

The ugly:

- The kit was advertised as coming with a diagram to help with installation. It does come with a diagram and a spreadsheet listing the IDs and lengths for the hose in the kit. However, the color is not listed, but I was able to guess which is which. But the diagram is the worst. It is a hand-drawn diagram that does not contain any information about the air pump and EGR systems. It also does not tell you which diameter hose to use where or which color - it's all uniformly black and white. I serious thumbs-down for this diagram. However, a good one that includes colors and diameters does not seem to be available at all. I was left guessing most of the time.

Below there are some pictures of the engine compartment from three sides with the air cleaner removed. It shows some of the interesting emissions componentry on the 1976 2.0, like the air pump (the thing sitting on top of the fan housing) and the EGR valve and air filter inlet connection (to the right of the air filter).

I saved all the hoses and plan on creating my own diagram, complete with diameters and colors and lengths.

View from drivers side:


View from passenger side:


View from rear:


Hope this helps someone.

Posted by: tod914 Jul 29 2006, 02:20 PM

Let them know your missing lines and they should send them to you. Happened to a friend was easily resolved.

Posted by: Dave_Darling Jul 29 2006, 04:44 PM

I am quite sure Pelican would be very very happy indeed to host this once it's done!!

--DD

Posted by: RustyWa Jul 30 2006, 10:51 AM

Looks like the hose from your AAR valve is kinked. This could cause some warm-up issues if the engine doesn't get the extra air it needs.

Posted by: RustyWa Jul 30 2006, 10:53 AM

Just looked again..the picture from the drivers side doesn't look that bad.

Posted by: type4org Jul 30 2006, 11:01 AM

That's not it - the hose looked fine and I replaced it along with almost all vac hoses yesterday. Issue still there. Just now I removed the AAR and will do some simple testing. It does let air through at ambient temp (high 80s now), but will be warming carefully in the oven to make sure opening/closing works correctly.

Posted by: Bleyseng Jul 30 2006, 12:20 PM

Just plug it in to a 12v source off the car (battery) and see if in 5 minutes its nearly closed. Probably not so squirt some PB Blaster into it and leave it over nite as that will free up the rotary valve inside.
It also should free warm to the touch as there is a heater in the bottom.

Posted by: type4org Jul 30 2006, 12:27 PM

I have tested it cold (short time in the freezer), at ambient temperature and heated up (short time in the oven), and it seems to work fine. It did start closing in the oven. Internal resistance is 13.5 Ohms, that seems fine as well. The last test I want to do is heat the engine up and then try to blow air into the air filter-to-AAR hose to see how much gets through. At any rate, I doubt the AAR is causing the problems when cold.

Another cold running symptom is that it wants to stall whenever I push on the gas pedal. I have to push down more to get over the "hump". Either there is not enough enrichment at that moment, or too much. This symptom is much less pronounced when warm.

Posted by: Bleyseng Jul 30 2006, 05:10 PM

1.check for a vacuum leaks using propane, starting fluid etc

2. Check your timing as it sounds like that too as the "hole" might be that

Posted by: type4org Jul 30 2006, 05:20 PM

The car is going into the shop on Tuesday and will get the mechanical/igition side checked out and adjusted. I'm also having all the fuel lines replaced and will ask them to check the fuel pressure at that time as well. The seller had to replace the fuel pump, maybe the pressure is incorrect.

With the exception of the lines from/to the charcoal canister all vacuum lines on the engine have been replaced. Major drag at 95 degrees temperature! Unless there are other spots that could leak vacuum I'd consider that part taken care of.

Posted by: Hoss Jul 31 2006, 11:48 PM

Jens,

Here are some other pics I took of my '76 with smog equipment as requested by Geoff Bleyseng in another thread. I thought I would post it here in case you decided to do a full write up with the correct routing for the Bird Board to host. I can take additional photos if there are specific requests.

Note that I do not have a hose on the part just under the smaller air filter. I checked your photos and could not see a similar angle for comparison.




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Posted by: Hoss Jul 31 2006, 11:50 PM

Next shot



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Posted by: Hoss Jul 31 2006, 11:51 PM

Another one.



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Posted by: Hoss Jul 31 2006, 11:53 PM

Another one.




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Posted by: Hoss Jul 31 2006, 11:55 PM

Yet again.


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Posted by: Hoss Jul 31 2006, 11:57 PM

From the other side.



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Posted by: Hoss Jul 31 2006, 11:58 PM

Driver side.


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Posted by: Hoss Aug 1 2006, 12:01 AM

Last one for now.



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Posted by: type4org Aug 1 2006, 05:09 AM

Thanks for the pictures. I'm assuming your distributor advance side is not hooked up? On mine someone hooked up the advance where the EGR is hooked up on the throttle body and left the EGR disconnected. I have changed that since.

I'll check on the air pump connector from your first picture either later today or tomorrow. One single day before I had a regular appointment at the shop to have all rubber fuel hoses replaced the dang thing decides to drip gas from underneath the tank and I had to have it towed to the shop That's where it's at right now.

I am assuming your vacuum hoses have all been replaced at some point, right?

Posted by: Hoss Aug 1 2006, 02:05 PM

Yes, on the vacuum hose replacements. PO records indicate that some of the hoses were replace in 1988, and one in 1993. It looks like some of them are actually newer, but I do not have a definitive replacement date.

I need to check the distributor advance to see if it is hooked up. I will get back to you on that, and look forward to your update after you get your smog check.

Posted by: type4org Oct 15 2006, 06:13 PM

Sorry for the huge delay - only a few days ago was I able to replace the last line in the engine compartment, after having traveled 6 weeks and then repeatedly ordering just enough hose to *not* cover all my needs

Today I took all the vacuum/gas tank ventilation hose that I had carefully numbered and took measures, which I then compared against what I could find in the Porsche parts list and against Dave's existing diagram on the Pelican site. As the listing explains, after 30 years any hose will discolor and shrink, so I did not trust my ID measurements fully and the lengths were a little hard to accurately measure with pieces eternally set in their curvy routing position.

Since I am not artistically inclined I collated the information verbally, in a spreadsheet form. Connection point positions are described as clock face positions for those parts that have more than one hose connection. Imagine the clock by looking onto the engine from the top and the 12:00 position towards the front/passenger compartment, and the 6:00 position towards the rear/transmission.

To make sure everyone can read the information I am attaching it as PDF and RTF (rich text) format. Dave: If you can use this information to create a new diagram or extend your existing diagram, please do.

RTF:
 76914vaclines.rtf ( 2.6k ) Number of downloads: 215


PDF:
 76914vaclines.pdf ( 27.12k ) Number of downloads: 247

Posted by: rdauenhauer Dec 9 2011, 01:07 PM

There is a lot of "stuff" on a CA 76 2.0L !
Restoring one myself I found not much detail on the variant power-plant but this was the best thread I could find.



One question I have is what is the correct throttle body?
Early units had 2 vac ports on either side of the unit. The rearward one connected to the adv(retard ?) side of the VAC can on the distributor. The retard side of that can open to the atmosphere.
Later TB's deleted the opposite nipple.
As it related to the correct vac line routing the example in this thread shows both?

Posted by: rdauenhauer Dec 11 2011, 09:15 PM

Ah come on!! Arent there any late (75/76) & CA owners out there?
While the provided sheet is useful I'm a visual kind of guy some pics would really help.

Posted by: PancakePorsche Dec 12 2011, 01:30 AM

I have a California 76 and the EGR is connected to a "tee" in the vacuum line going from T.B. to distributor advance. Whether or not the EGR is working should have no real effect on your idle problem, however it does make a mess in the throttle body when it is working. Check T.B for cleanliness especially in the idle air bypass adjustment for idle speed.

Posted by: rdauenhauer Dec 12 2011, 03:50 PM

...Huh? What idle problem?
Im not sure what you are responding to but my focus was to get some information
& visual example of a complete & unmolested LATE (& CA) 2.0L engine & its accompanying vac. hose layout.
The original thread was as close as I could find after a search, but neither the OP or the other contributor have been active for yrs.
Can you post some detailed shots off your motors vac. & emmisions connections?
Thanks

Posted by: Jeff Bowlsby Dec 12 2011, 06:50 PM

Rich, Wouldn't it be similar to a combination of the late 74 2.0 and 74-75 1.8 which includes the EGR?

The CA '76 2.0 vacuum hoses should be identical to the Late 74 2.0 with the following revisions:

1. The charcoal filter moves over along side the battery and taps its supply from the passenger side of the fan housing (rather than the drivers side as shown on the 74 diagram).

2. The smog pump supply hose routes to the air injection tubing connection.

3. The EGR tube vaccum supply T's off the distributor advance tubing like the 74-75 1.8L

Looks like we need a diagram of this for reference.


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Posted by: rdauenhauer Dec 13 2011, 02:29 AM

Not exactly, also
There is no flashback valve on the late cars (no head vents).
The late system doesn't use the stacked elbow on the plenum (plenum is different).
(D-Jet) TB's will have only one Vacuum port (?).
There are two configurations CA & non-CA
That Ive seen, non-CA don't use the EGR valve just the air injection plumbing
while CA cars have the additional valve & piping connecting back to the muffler + the additional electronics

I guess Ill take a crack at it.

Posted by: JeffBowlsby Aug 5 2022, 01:49 PM

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