Mamooguy

So I was under the hood today, finally getting around to replacing the lousy old vacuum lines (1987 NA 944). Not to mention putting lines in where none existed previously!

Unfortunately not being up on all the technical terms, I'm a little bit stuck.



What I've done so far:

1. Throttle housing to pressure regulator and pressure damper

2. I think I did the shutoff valve to temperature valve (hose was missing).

However, some probs:

-- I'm not sure exactly where all these parts are. The temp valve is by the firewall, right? Under the intake manifold? The other line from that, which according to the diagram is supposed to go to the throttle body, seems to go to the brake booster (which I presume is the big disc-like dealie in front of the fuse box?).

-- The diagram shows the lines to the fuel rail also going to the control valve, but the old one I pulled out was just a three-way to the fuel rail ... what's the deal there?

-- There's what seems to be a spare vacuum line mounting on the throttle housing, which according to the diagram goes to the temp valve, except there doesn't seem to be a spare there (as I said the other one seems to go to the brake booster).

Note: I'm using the Lindsey Racing silicone vacuum line kit.

Worth noting, the work I've done so far hasn't hurt the engine, it still runs fine. In fact I could be mistaken but the idle seems a hell of a lot smoother.

Oh, and one last point: I'd also like to do the vacuum lines for the cabin heating system, but that too has me confused!

Sorry for the n00bness ... it's just that it all looks a bit spaghetti-like to me.

GodSpeed

Post a working pic of what you have so far. Then we can tell you whats missing.

Mamooguy

Ah, good idea.

Oh and on closer inspection I realize I was mistaken ... the other line from what I assume is the temperature valve goes to the shutoff valve housing below the saucer (maybe it's the control valve, I'm not sure). Which still seems wrong.

The whole compartment:



The throttle housing (the vacuum line mounting thing is clearly visible in the centre):



What I've got circled here ... is that the temperature valve?

GodSpeed

Yes thats the temp valve, I will go shoot a pic of mine and post up.

Mamooguy

Aha, so the routing is wrong ... the other line in the temp valve should go to the throttle housing, with a third line from the fuel rail line branching off to the control valve?

How about the other lines, from the intake pipe (wherever that is) to the ejection pump (wherever that is)? Does that use the little silicone lines, or fatter ones?

Mamooguy

And while we're on the subject of vacuum lines, am I correct in believing the control valve is located right at the back of the engine block, sandwiched between the cam cover and the firewall?

If so, I think I've finally figured it out!

GodSpeed

Heres a pics of when I first bought the car:



Here the engine as of a few months ago:




Theres also a line that goes from a plastic thingy in the battery compartment to a fitting by your drivers side shock tower, it runs along the top of the firewall.

Mamooguy

Ah, okay ... so let me see if I've got this right?



A (actually slipped too low to be seen) is the control valve
B is the shutoff

Is that right?

Mamooguy

Update: I got it done! And holy crap, what a difference it makes!

1. There used to be an incredibly annoying rattle that got louder as I accelerated, and now it seems to be gone.

2. The idle is glorious, totally rock-steady. Before it used to fluctuate like someone was slowly pumping the gas pedal, but now it doesn't budge at all!

3. The brakes are far better than before. Oh, they always worked, but oddly -- they used to pulse, as though there were ridges in the discs or something (in fact someone diagnosed the problem as warped discs). But no more! I think I can still feel the slightest brake-shudder, but it's really hard to tell.

Anyway the car drives better and sounds better. Hooray!

I recommend doing the vacuum lines to everyone who hasn't gotten around to it, especially if you've got missing hoses (like I did).

ttwirz

I know its a bit late but figured I'd throw this in for future. I was doing a leek check on my vacume hoses and that temp thing in tha back was leaking. the rubber top was actually leaking not the hoses. From the research I did I found it goes from the side of the throttle body to the the temp sender over to a diaphram by the power brake booster. that dyaphram lets fuil vapor into the intake once the care is warm. I ended up just running from throttle body to diaphram and it ran fine.

WizPorsche944

Did you guys also change the Fuel Vapor diaphragm ?