vents lines in trunk

I've copied and pasted this from another post because I have a question about it. (Actually three questions)

"The vapor separator in the trunk has nothing to do with the lights. It is not connected to the fuel pump. The vapor separator is a condenser separating fuel vapor from liquid fuel in the fuel tank vent line. Vapors go to the charcoal cannister located in the engine compartment, and the liquid drains back into the tank. If the lines to the vapor separator are damaged or missing, then the trunk can start smelling like gasoline. The vent line for the fuel pump does not contain fuel vapors and does not connect to the fuel tank vent line. The vent line for the fuel pump is less than 1/8" I.D. and vents into the trunk to help prevent dirt and water from getting into the fuel pump."

Question: All lines except one are hooked up. It appears that one line goes through a hole in the bottom of the trunk and then ends. It has a machined fitting on it and is sealed by a rubber compound. Is this just a "vent" or should it be attached to something under the trunk?

Second question: Under the bonnet just behind the washer fluid tank is a canister (assume for smog) with three lines. One of these lines comes from the canister in the trunk, the other goes to the top of the valve cover and then the third goes to the carb (ZS) (There is a four on the bottom of the canister that goes to the run-on valve.) The 90 degree tube on the valve cover has been plugged. Shouldn't this be clear?

Third question: The vacuum sized tube going from the anti-run-on valve is also plugged. From photos of other engines, it appears to go the the carb but I cannot find where.

Question: All lines except one are hooked up. It appears that one line goes through a hole in the bottom of the trunk and then ends. It has a machined fitting on it and is sealed by a rubber compound. Is this just a "vent" or should it be attached to something under the trunk?

Second question: Under the bonnet just behind the washer fluid tank is a canister (assume for smog) with three lines. One of these lines comes from the canister in the trunk, the other goes to the top of the valve cover and then the third goes to the carb (ZS) (There is a four on the bottom of the canister that goes to the run-on valve.) The 90 degree tube on the valve cover has been plugged. Shouldn't this be clear?

Third question: The vacuum sized tube going from the anti-run-on valve is also plugged. From photos of other engines, it appears to go the the carb but I cannot find where.
Question #1, You need to give a description of where the line going through the trunk floor is coming from. There is more than one line that goes through the floor. From the vapor canister in the trunk, one line goes to the top of the gas tank, the other goes to the charcoal canister in the engine bay. There is another small line that is a vent line for the fuel pump. Usually clear tubing.

Question #2, The canister is filled with replaceable charcoal and is a smog related item. Yes, the valve cover vent tube is supposed to be open and vented into the canister to help ventilate the crank case and draw off engine fumes to be redirected to the carburettor.

Question #3, No vacuum lines are supposed to be plugged! Where the line connects on the ZS carb, I'm not sure, but probably ported vacuum. You'll need information on a ZS carb for this.

A little extra help. http://www.mgexperience.net/article/mgb-pcv-system.html (http://www.mgexperience.net/article/mgb-pcv-system.html)
Go to the bottom of the list for 1975 0n. Some things are the same as on earlier models

After a close inspection, I think that line must go to the top of the gas tank. I could eliminate the one that goes to the canister (I traced it), and also the one going to the pump. So, that must be it. I can only assume someone has plugged that as well, so dropping the tank is another on the list to do.

I'll unplug that vent tube then. Just wanted to be sure. There is nothing in the canister, so (may sound silly), where do I get that type of charcoal? I've never sent it at an auto parts store (Not that I was looking)

I've looked all over for a possible port on the carb. Unless, that too has been "modified". I'll keep checking, researching, etc.

Thanks for your tips. I've just got so many little things to try and correct.

If you don't mind:

Two more questions:

There is some sort of relay beside the inertia switch. I believe the fuel gauge is wired to it. What is it? One of the contacts is bare.

Where can I find a photo of a voltage regulator? I do not think there is one "built in" to the alternator. I think it might be located on the right side fender well. I think I need to locate it and replace it.

I would be happy to email one or two photos to help clarify my questions, etc.

After a close inspection, I think that line must go to the top of the gas tank. I could eliminate the one that goes to the canister (I traced it), and also the one going to the pump. So, that must be it. I can only assume someone has plugged that as well, so dropping the tank is another on the list to do.

I'll unplug that vent tube then. Just wanted to be sure. There is nothing in the canister, so (may sound silly), where do I get that type of charcoal? I've never sent it at an auto parts store (Not that I was looking)

I've looked all over for a possible port on the carb. Unless, that too has been "modified". I'll keep checking, researching, etc.

Thanks for your tips. I've just got so many little things to try and correct.

If you don't mind:

Two more questions:

There is some sort of relay beside the inertia switch. I believe the fuel gauge is wired to it. What is it? One of the contacts is bare.

Where can I find a photo of a voltage regulator? I do not think there is one "built in" to the alternator. I think it might be located on the right side fender well. I think I need to locate it and replace it.

I would be happy to email one or two photos to help clarify my questions, etc.

The following is a link for rebuilding your charcoal cannister.
http://www.theautoist.com/carboncannister.htm

You don't state the year of your car so I can only guess about the following.
The fuel gauge gets power from the voltage stabilizer.
Not all years have an inertia switch. The inertia switch is designed to cut power to the fuel pump, not the gauge if the car is violently jarred in a wreck.

I would have to look at the wiring diagrams to see what years had an external voltage regulator for the alternator. Most years that have the alternator, have a voltage regulator built into the alternator.

What color are the wires going to the item you think is the voltage regulator?

Wiring diagrams are available at http://www.advanceautowire.com click on stock schematics.

Do you own a Bentley factory service manual? There are diagrams of the various parts in it.

I'll unplug that vent tube then. Just wanted to be sure. There is nothing in the canister, so (may sound silly), where do I get that type of charcoal? I've never sent it at an auto parts store (Not that I was looking)

You can buy charcoal at a fish tank supply store.

I've looked all over for a possible port on the carb. Unless, that too has been "modified". I'll keep checking, researching, etc.

If there isn't a port on the carb then it must be manifold vacuum.

Thanks for your tips. I've just got so many little things to try and correct.

If you don't mind:

Two more questions:

There is some sort of relay beside the inertia switch. I believe the fuel gauge is wired to it. What is it? One of the contacts is bare.

It is a voltage stabilizer for some instruments. Gas and temp. It should have 2 wires going to it. Easy to replace. Not expensive. If it's original, it probably doesn't work properly anyway as it has points inside. Some new ones are electronic.

Where can I find a photo of a voltage regulator? I do not think there is one "built in" to the alternator. I think it might be located on the right side fender well. I think I need to locate it and replace it.

Does the alternator have a black cover about 2 inches deep on the rear end? If it does, it's a Lucas. If it's a Lucas, the voltage regulator is inside. Most starter and alternator rebuilders will rebuild them for around $60.00. Most alternators have internal regulators! In fact, I've never seen one without it. Go here for photos of a Lucas and a Delco conversion.
http://www.teglerizer.com/alternator/index.html

I would be happy to email one or two photos to help clarify my questions, etc.

Hope this helps. Go to this "Moss" web site, if you haven't already, and request a free catalog. There's a lot of info in it with some part descriptions and locations.

https://www.mossmotors.com/CatalogRequest/RequestForm.aspx