You've got my attention.
You did your part, now I'll chime in.
First, let's talk about the three vacuum lines. They are on the back of the carb.
The line going between the vacuum advance on the distributor and the three ports on the back of the carb? That should plug in at the top.
Follow your diagram; the bottom nipple is for the line which goes to the transducer (snaps into air cleaner housing).
The middle nipple goes to the (BVSV) vacuum switching valve. Clear as mud?
Next, take a look at the manual if you have time. I do not take credit for this, but I did put it in order for you:http://s145.photobucket.com/albums/r211 ... %20Manual/
The manual will describe how to test your microswitches. Personally, I wouldn't worrry about them at this point.
You are going to replace hose A which is a tube which is open from the charcoal canister and won't affect the idle, but will cut down on any fumes you might smell under the hood.
It goes to the 'bowl vent solenoid'.
As far as plain adjusting, you will adjust the idle when it is cold, adjust the idle when it is warm, and then adjust the 'Idle Up Actuator' to compensate for an electric load when the car is warm.
Of course, the O2 sensor should be replaced as it tells the ECM that it will now control the MCS and the mixture.
Here is how to adjust the idle.
Roman Numeral 2 - adjust first; cold idle
Roman Numeral 5 - adjust second; warm idle (wax thermoelement will no longer hold idle up high when warm coolant is circulating through it.)
Roman Numeral 3- adjust last, once the other two are correct. It shows the gap but you will adjust by turning the screw inside the Idle Up Actuator.
Hope I've got the sequence right.
Let me know if I made a mistake.
If your A/C is working, it has a separate idle up actuator.
It is Roman Numeral 4 and the one you adjust after the first three.
Roman Numeral 1? Bottom part of 'thermowax element'. They are pretty bullet proof.
You've got to get that adjusted pronto when you first fire up a cold MK1.
The carb in your picture is a B2 and in seemingly pristine condition. If so, that MCS is well overdue.
It is the correct carb for a 5 speed with A/C, as you appear to have, although you did NOT provide more wide angle pictures.
(see, there's a reason I asked for pictures...)
When most people rebuild the carbs, the B2 gets washed off unfortunately. Do us all a favor.
If you DO clean that carburetor, skip the top of the thermowax element. Leave those model numbers intact. And don't immerse it in some stupid old carb cleaner. Just shoot a gentle spray of plain old Simple Green on it, give it a LIGHT once over with an old toothbrush, and rinse with tap water. Your engine will thank you for it.
Other model carburetors include:
depending on MK1 model, and accessories, so you will understand that asking for a rebuilt carburetor without supplying the model number or application
is like asking Moderator Suprf1y to grind you a cam without specifying the lift and duration or year make and model. There are variations even within years. It goes from the sublime to the ridiculous if you ask for a 'friend', and can't supply a single picture. But I digress.
At the end of the day, if you cannot adjust the cold and warm idles within a few minutes and it just 'dies' when it drops below a certain rpm
, then you have to suspect the 24 year old MCS. Do a visual inspection of the two MCS wires and see if they have been soldered.
Before you throw in the towel and decide it needs a rebuild, here is the FIRST place to start.
You only need a keen eye:
On the passenger side, there is a sight glass.
You should be able to see the gasoline/air level at the middle of the sight glass.
Unlike other carburetors, this is not adjustable without removing the top.
So the obvious question is: Can you see the level in the sight glass?
You cannot adjust the idles...warm, cold, idle up, A/C idle up until that fuel level is correct.
Hope this helps. I am no expert, but there are a few members here who can steer you right.
...and that, Mr. jrockflimflam is how the cow ate the cabbage.
Let us know what happens, and make sure to supplement your information with some pictures and/or video if you are serious about getting more 'in depth' help. No one here has a monopoly on information...that's why Teamswift was created!