1974 1.8 project car. My fuel system resto is finished, the tank is back in the car, and I have questions regarding the expansion tank and charcoal cannister. First, the cannister is not installed (I have the correct part) because the hoses from the front to rear of the car are gone.

My tank has a small OD hose bib just below the gas filler cap. It has been pinched closed. Where did the hose originally attached to that bib connect to?

I have a somewhat flexible hard plastic line that passes through the center tunnel. It is not connected at either end. Where did its ends originally connect to?

What lines connected to the small OD hose bibs (2) on the expansion tank?

With the small OD hose bib at the gas cap pinched closed, can the tank vent enough past the filler cap, or can this be a source for poor running?

I have Clymer and Haynes manuals, neither shows how the cannister or hose bibs on the tank should be hooked up, can someone provide me with a diagram for the USA '74 car?

BTW; I have found the holes, used for the large diameter cannister hoses, under the rocker panel at the rear of the car, but cannot see where those hoses enter at the front end of the rocker panel. I would be willing to restore the charcoal cannister system with a proper diagram, as well as any advice regarding the forward hose entry point.

Thank you.

Here is a link for the complete front/rear fuel system hose layouts for a 1.8l engine. It's on the pelican parts website:

http://www.pelicanparts.com/914/technical_...4_18FI_diag.htm

On a 74 and later, the charcoal canister was in the engine compartment. There was a 7mm plastic line that ran from the tank to the engine compartment. It hooked to the overflow tank at the front, and to the canister at the back.

There were two places to mount the canister, one was on the battery tray, and the other was on the back wall.

We discusssed this at length recently...I think it was resolved this it the correct diagram. Should have a single port throttle body.

OK, guys, help me iron out some wrinkles. Your info is very helpful, and for that I thank you! Now, some more details.

1. My throttle body has a single port vacuum connection.
2. I do have a plastic line that passes through the tunnel, but it's not 7mm. More like 4/5mm (light blue line in Jeff's diagram - I can measure it later).
3. There is no evidence that my car ever had the CC mounted in the engine compartment, but if I did that it would certainly simplify my problem (although I worry about fumes). I did find holes, for large OD (13mm) CC hoses, behind the rear of the left rocker panel, but there are no holes at the front (that I've found).
4. That leaves; my car has a tank vent (small OD hose bib) on the fill cap tube, and TWO MORE small OD hose bibs on the expansion tank. This is the big problem - none of the diagrams that I've seen show THREE front, small OD, hose connections. The two bibs on the expansion tank face to the left and to the right, one each. The single bib just below the gas cap faces back (toward the dash).

The PET reads as though the CC is mounted above the tank, close to the brake fluid reservoir. Unfortunately the PET isolates the system and doesn't show how all the hoses hook up, and which, if any, vent to the atmosphere.

If my CC is front-mounted, I can figure out how to get the 13mm hoses to the fan shroud and air cleaner. But which of the three small OD hose connections are used with the tunnel line? Or is the tunnel line only used for a rear-mounted CC? And if it's used for a rear-mounted CC, which of the three front hose connections is used (see next paragraph)?

Now for my biggest reason to get this right, other than to avoid poor running because of insufficient venting in the gas tank, is to avoid gas smell/fumes in my garage. So, to tie this in a bow, do I rear-mount the CC, and connect the tank-vent line (at the gas filler cap) under the expansion tank to its left side hose bib, then connect the expansion tank's right side hose bib to the line in the tunnel? If this is correct it would be a "sealed" system, which I think is the whole point. Or do I reverse the two lines (they are the same size) on the expansion tank? Or...?

OK, in thinking about this more, putting the CC in the engine compartment will solve a host of problems. It will allow me to easily connect the CC to the fan shroud and air cleaner housing. It will allow me to incorporate the 5mm tunnel line as intended.

Now, all that remains is do I connect the tank vent hose bib to the left or right side of the expansion tank/chamber, and connect the tunnel line to the other side (left or right) of the expansion tank? In other words, are the connections on the expansion tank reversible (as a reminder the left side bib is at the top of the expansion tank, while the right side bib is on the bottom of the expansion tank)? The link to Pelican (thanks Jim H.) shows that the inboard hose bib on the expansion tank is the connection used for the tunnel line. To me, this makes sense, because if the lower, outboard bib was used there would be a possibility of liquid gasoline entering the tunnel line, rather than just vapors.

BTW; THANK YOU!!! for the diagrams. They showed me that my car had redundant decel valves installed - one factory ('74-type) and one with home made hoses/connectors ('75-type) - and I had already made the decision to eliminate the home made one but was nervous about doing it!