Vacuum hose help

[BOOMER]

My 75 914 has 2 vacuum hoses coming off the distributer. Diagram shows one going of to the egr valve. The PO who has owned the car for 25yrs. said the car never had one and I read it was Cali. only cars that had these, this car has been east coast all its life.Right now its just laying there. Doesn't seem right to me, any Ideas??? By the way car seems to run fine the way it is.

[Dave at Pelican Parts]

Is yours a 1.8? Our 75 diagram is specifically for a 1.8 with EGR system, which I think was CA-only (or maybe CA and one or two other areas).

Many of the 74+ 914s did not have vacuum advance. It's easy to tell if yours has it or not: Ones that have it will have two fittings on the throttle body. Ones that do not will have only one--the retard fitting.

914s without the advance fitting still had the distributor dashpot (the "vacuum thingy") with two fittings, though. I'm guessing that's because it was cheaper to use the same one on all the cars. Anyway, what they did with the cars without advance was that they left the hose from the advance fitting on the dashpot unhooked. They usually tucked it under the manifold just to make it look better.

--DD

[BOOMER]

Thanks Dave, Its a 1.8 and I only have one port on the throttle body. Did the hose to nowhere stay plugged or unplugged?

Tom

[Dave at Pelican Parts]

Unplugged. Even with it unplugged, there should be no path for air to leak into the intake this way. If there is, the diaphragm inside the dashpot is blown and you need another one.

I am told (but cannot confirm this) that plugging the hose can result in the vacuum retard coming in a little differently, because the air on the "other side" of the diaphragm is not free to move and to allow the diaphragm to move more freely. The theory sort of makes sense to me, and even if it's wrong it shouldn't hurt to have an open hose that doesn't create an air leak...

--DD

[BOOMER]

Thanks Dave, a quick pic of the offender.......

[Tidybuoy]

I have a '74 1.8 and I had the same question when I first got the car.

I have a great book (914 Tech Tips by Dr. 914). This book has helped me solve various problems over the years and in this case, it says to put a 4" piece of hose connected to your distributor and the other end is left "open to the wind", meaning not plugged and not connected to anything.

Dave had a good idea of tucking it under the manifold just to keep things looking nice.

By the way, well you're looking at the engine compartment, you might notice 3 white wires, near the battery, that go to nothing. These may be taped up and hidden. These wires go to an optional altitude sensor that was only available in 1974.....I wouldn't mind getting one of these as I drive up to the mountains from time-to-time.

Vern

[BOOMER]

Thanks Vern, I'll throw the book on my fathers day list.

[Pete000]

I have just encountered this situation on my 74 1.8. I know my lines are not currently running as per the diagrams posted here and o Bowlsby's site.

I have only one air line on the throttle body (retard), but two lines at the distributor (retard and advance). After reading this thread I understand that only one line on the distributor is necessary (retard) and the other can be left open (Advance).

I see in the Bowlsby diagram it mentions to leave the hose #2 (the one pointing rearward towards the distributor cap) open to vent to the atmosphere.

Sound correct??

[Dave at Pelican Parts]

Hrm. If that's what Jeff's diagram says, then he and I disagree on which to leave open and which to plug in.

And that worries me... One of us has to be wrong, and he's got a pretty solid grasp of most of this stuff.

--DD

[Pete000]

Originally Posted by Dave at Pelican Parts

Hrm. If that's what Jeff's diagram says, then he and I disagree on which to leave open and which to plug in.

And that worries me... One of us has to be wrong, and he's got a pretty solid grasp of most of this stuff.

--DD

Here is Jeff's diagram...This is how I was going to run it, but sounds like it might not be right (line #1 should go to the retard port on the dist. and the advance port on the dist. vented to the atmosphere). I will set it up plugged into the retard port on the distributer. I haven't tried it yet due to needing a replacement AAR valve...I won't even tell you how they had mine plumbed. It was not even close to correct. I am surprised it ran at all !

[Pete000]

Another from Jeff's site.

[Pete000]

How about this??

Look Correct?

[Dave at Pelican Parts]

Yes, the second picture is exactly how I thought it should be. The advance line is unhooked, while the retard is hooked up.

If both ports are present on the throttle body, both lines get hooked up of course.

--DD