1977 - trace small CIS vacuum line

[kach22i]

I recently replaced some small vacuum lines (going to and from the WUR) and larger oil breather lines on my CIS 2.7L. However I cannot remember where the line off the throttle body (behind the air box intake cover - upper left) goes to.

I have looked at many diagrams and photos of actual engines, but still feel like I'm just guess at it. I want to get it right, pictures will help trace this line if you don't mind.

EDIT - wrong photo removed

NOTE - 1 : edit, photo removed

NOTE - 2 : There is a fair amount of sucking going on through this line with the engine running.

Actual engine:

[Cipotifoso]

I've got it going to the distributor vacuum advance.

[kach22i]

Originally Posted by Cipotifoso

I've got it going to the distributor vacuum advance.

Really? Are you sure?

Maybe you are thinking of the two nibs on the backside of the THROTTLE BODY far from you.

I'm talking about the one on the front nearest you as you work on the car.

My distributor vacuum advance has always been blocked off and capped.

[930 slant nose]

vacuum distributor

[Cipotifoso]

I'm sure - I went out to the garage to check it before I answered.

[stlrj]

The cap on the vacuum retard is not something that is OEM but the vacuum hose that goes nowhere is.

[kach22i]

I must of took off a cap plug off of the throttle body vac and not a small hose, that is all I can think of. I've been unable to test drive the car until just yesterday and discovered that car was not running right under load. I replaced the hoses almost three weeks ago, it was idling and revving up just fine - that is until later under real life driving loads.

The only reason I've doubted the vac retard destination everyone agrees on is that based on what I could remember from doing the Seafoam thing, is that the vac retard was one of the two connections on the backside (blocked off and not in front).

I will hook up the single throttle body line to the vac retard on the distributor and see what happens.

Thank you; 930 slant nose, Cipotifoso, and even the sarcastic stlrj.

My hoses do not match the diagrams, I'm considering getting extra line and splitters to copy/restore. However, will wait until I see some engine bays of similar era cars in person before I attempt this.

[Scrappy]

If you have a vacuum port on the base of your WUR (not the big one on the top) is where mine is plumbed in on my 914/6 2.7L. You could also tee the distributor into the line. That port is below the butterfly and sees manifold vacuum (negative pressure to be PC).

The big vacuum port on the WUR we hooked with a tee into the auxillary air regulator (big can on the throttle body) vacuum line.

While certainly not experts, we have come to the conclusion that the factory didn't document proper hookup. We fooled around until the method we hooked the system up resulted in the proper A/F under all conditions (and good starting/running characteristics).

Just my opinion only.

[kach22i]

Originally Posted by Scrappy

While certainly not experts, we have come to the conclusion that the factory didn't document proper hookup.

Thanks Scrappy, you are right, all of the diagrams I've seen seem to exclude 1977.

I hooked up the throttle body line to the vac retard on the distributor, no improvement. I pulled the air box cover and noticed the second nib.

I'll rephrase the question: Where do these two lines go?



I have no idea how I goofed up so badly, might of been the parts run I made in the middle of the project. I just lost track of things trying to get an inch count on the amount of line I needed - I guess.

[azasadny]

George,
You better get your car squared away in time for next Saturday's drive! We're planning on attending and it will be a long drive for us, but we're looking forward to seeing you guys!

[Oh Haha]

Originally Posted by azasadny

george,
you better get your car squared away in time for next saturday's drive! We're planning on attending and it will be a long drive for us, but we're looking forward to seeing you guys!

+1

[kach22i]

Well I've managed to restore everything back to how it was before I replaced the hoses. This is not to claim everything is as Porsche intended, it's is what I have.

I've sealed up some leaks with clamps and gasket sealer, may have to get the right size hose (#1) Monday. One I had on hand was to small and restricting things, the other just a little too easy to slip on but had the car running better. I went with the larger one as the spouts are larger on each end of #1 compared to the line #2 ends.

I have other issues, which as it happens strike while I'm trying to sort out the last mistake I made.

I'm suddenly running rich (at least after using starting fluid to check for leaks) and missing, sluggish and poor idle at warm up. All this without even test driving it.

I suspect the Pertronix Ignitor and or the distributor. I have a spare Pertronix Ignitor so I'll try installing that in the morning and use the old one as a back up spare.

I've tried using the old rotor but things were worse if anything. I have not changed back to the old cap, but may try that before messing with the Pertronix Ignitor.

What are the symptoms of a bad Pertronix Ignitor? Can they go bad intermittently, partially or just fail 100% without notice? I've had mine in for about seven years with no problems, what's the expected lifespan on these?

Back to how it was.........


EDIT: Looks like the Pertronix Ignitor is as good as any place to start..........
http://forums.pelicanparts.com/porsche-911-technical-forum/235248-pertronix-caveat.html

[Oh Haha]

I wouldn't suspect the Pertronix gizmo, George. I would try to adjust your idle with the idle mixture screw. It's directly behind the throttle body.

If you had vaccuum leaks you may have caused your richness by fixing them.

Your fuel mixture screw, located in the fuel distributor, may need adjusting as well but I would start with the easiest change for now.

[Scrappy]

If you mess with your idle mixture, do it 1/8 of a turn at a time and let it stabilize. Gross adjustments get you nowhere. That was advice from a Porsche mechanic I know.

[kach22i]

Originally Posted by Oh Haha

If you had vaccuum leaks you may have caused your richness by fixing them.

I checked for vacuum leaks twice before but not just before I changed the hoses. I never had a leak until after I changed the hoses and I know why and where now. Still I could have had leaks and not known it, so your theory holds water - thanks.

The Pertronix unit is just worn looking, I dropped a little liquid rubber on a exposed wire. Metal was showing at a 90 degree wire bend off the rectangular block just inside of the cap, fixed but a sign of troubles ahead if not responsible for my current woes.

I think the gas smell out of the exhaust was from cylinders missing. If not the Pertronix or the distributor then I must go up the line to other boxes/controllers (CDI/perma-tune) and more things like coils.

I'll be busy.

[kach22i]

Originally Posted by Scrappy

If you mess with your idle mixture, do it 1/8 of a turn at a time and let it stabilize. Gross adjustments get you nowhere. That was advice from a Porsche mechanic I know.

I've done this once before, have the special allen wrench already, 3mm?

I don't want to mess with the mixture when it's stuttering and missing. I'd get my ignition timing gun out long before that and see what's going on first.