Vacuum Gauge Connection

[J. Huber]

Another one of my basics, perhaps...

So where specifically do any of you hook up a vacuum gauge?

I tried the air side of the CSV but I guess it didn't work because it wouldn't hold...

(looking into fuel/air mixture adj.)

James
63 230SL

[Naj ✝︎]

quote:So where specifically do any of you hook up a vacuum gauge?

At the throttle body where you disconnect the vac line to the dizzy.
If you're adjusting idle air/fuel settings, connect using a 'T' peice. This is for a vac retard  :oops:

There is a vac port on top of the throttle body. Look for a brass screw -  and don't lose it!!

naj

68 280SL

[TheEngineer]

Please get yourself the BBB or the CD. Most of the information you are asking about can be found there.

[J. Huber]

Thanks Engineer. I have it!  :oops:

To be honest, I have the CD -- but don't always take the time to look through it. I also have Kenneth Ball's Manual which I stare at daily. Unfortunately, neither of these makes real sense to me until I have done the job at least once. Having you guys explain it in real life terms seems to help me the most. What can I say.

James
63 230SL

[J. Huber]

quote:Originally posted by naj

quote:So where specifically do any of you hook up a vacuum gauge?

At the throttle body where you disconnect the vac line to the dizzy.
If you're adjusting idle air/fuel settings, connect using a 'T' peice. This is for a vac retard  :oops:

There is a vac port on top of the throttle body. Look for a brass screw -  and don't lose it!!

naj

68 280SL

Thanks as always Naj. Prior to seeing the edited version, I tried the tee and white hose thing. Got nowhere. That explains it, perhaps. Is it normal that that hose does absolutely nothing that I can tell? If I disconnect it -- nothing changes. And with the Tee in there -- I had O vacuum...

James
63 230SL

[J. Huber]

And Naj, when you say "don't lose it" do you really mean "don't drop it because it will fall into the air filter canister area and not be able to be retreived until you remove the air hose, cannister lid & filter, then undo the bolts holding the cannister in place, and then...

Fortunately, I didn't drop it! But I have dropped things in there before (in case you couldn't tell.)

And that connection worked fine. I have a fairly steady reading of 13 on my gauge with idle setting about right (and since I am at 2700 feet above sea level --  I believe I add about 3?) Normal?



James
63 230SL

[TheEngineer]

That screw is a real dangerous thing. Like naj says, don't drop it: But it's so easy to do and for that reason I bought a little fitting that has the thread on one side(I believe it's M4, but it's been a long time)and a hose barb on the other side. It's permanently installed with a rubber cap over the barb end, when I don't use it. That way, I have to do the job just once. I dropped a little snap ring once: The one that holds the throttle lever to the engine block. It's hard to get to. I didn't find it for a long time. Finally I found it leaning against the rim of the engine block where the oil pan attaches. I could only see with a mirror. But now I have a spare. I can get real frustrated by little things like that.