engine and drivetrain Keep? Pull? Plug?

[bianchini]

I have been reading up on de-smogging my 74, and I'm looking for some last minute clarification on a few tubes/ connections....

 

In the first photo, there is are 3 tubes going into this small box on the firewall...

- The white tube runs from this to nothing (uncapped)

- The blue tube goes to the Carb

- The red tube goes to a little metal top-hat thing (in the other picture, labelled "R")

 

-what is this thing for and do I need it/ all these tubes?

 

In the second photo with the two metal top hats

- The "L" just has an electrical wire running to it and the tubes going out are capped. What is this for?

- The "R" has the red tube( mentioned above) and then a electrical wire running to it. What is this one for?

 

 

In the 3rd photo with the items in front of the the carb:

- the red boxed part goes below and is tied to the smog equipment. Can I remove this?

- the orange boxed part has tubes running to the fuel pump, the carb (2 tubes- White and black), and one more running towards the alternator. Im guessing this is part of the fuel delivery system, so I shouldnt mess with it. Correct?

 

I greatly appreciate the help everyone!!!

 

 

 

 

[esty]

if you are desmogging, you can remove all of those colored tubes and the vacuum relays on the firewall that they attach to

[bianchini]

I'm guessing the vacuum relays are those "L" and "R" pieces?

[Stevenc22]

I desmogged my '76

 

Here are some after pictures for comparison.

 

 

[Stevenc22]

The stuff in your first and second picture goes. Everything along the firewall goes.

 

The item in red in your third picture goes. The item in orange stays (This is your fuel return valve)

 

When done the only vacuum lines you will have left is one running from the carb throttle plate to the distributor and one running from a intake manifold to the fuel return valve.

[esty]

(This is your fuel return valve)

 

 

i'm curious...what is a fuel return valve...i have a 74 and a 76 that came with smog equip and i've never seen what you're calling the fuel return valve...

 

what's it's purpose and is it necessary, if so, why

[Stevenc22]

It is a vacuum activated valve that takes fuel from the fuel pump and returns it back to the gas tank when the carb doesn't need it. When you take your foot of the gas and the car is decelerating, the fuel pumps keeps pumping fuel but the carb doesn't need any fuel and so the vacuum of the engine activates this valve and send excess fuel back to the gas tank. Original solex carbs prefer the fuel return valve while weber carbs can do without.

[FunkyLaneO]

The 74 has a vacuum retard distributer so I wouldn't even run a vacuum line to it, it runs better without it. Since you have a Weber carb you can remove the fuel return valve and cap everything off, I don't have any vacuum lines left on my engine since I desmogged it.

[Simeon]

I desmogged my '76

 

Here are some after pictures for comparison.

 

You must be really embarrassed by the state of your engine bay. 

 

;-) 

Edited June 20, 2014 by Simeon

[Dev02]

I desmogged my '76

 

Here are some after pictures for comparison.

 

These pictures were taken in '76 when you bought the car... right? (massive envy)

[Stevenc22]

Taken last night. I bought the car as a rust bucket 2 years ago. Took hundreds of hours of my time to get the car to this level. But thanks!

 

Here are pictures of when i bought the car and the emissions stuff i removed.

[Dev02]

Night and day. Really impressive job.

[bianchini]

The stuff in your first and second picture goes. Everything along the firewall goes.

 

The item in red in your third picture goes. The item in orange stays (This is your fuel return valve)

 

When done the only vacuum lines you will have left is one running from the carb throttle plate to the distributor and one running from a intake manifold to the fuel return valve.

 

 

Do you mean running a line to the vacuum advance on the distributor. That's the only place I see where it could go....

[Stevenc22]

Yes, in my middle picture you can see my vacuum line running from the base of the Weber carb to the vacuum advance on the distributor.

 

The L R vacuum canisters have electrical wiring attached to them and all of it can go EXCEPT the resistance wire which powers the coil. That can be cut out of the blue cover and must be put back in place.

Edited June 20, 2014 by Stevenc22

[bianchini]

Yes, in my middle picture you can see my vacuum line running from the base of the Weber carb to the vacuum advance on the distributor.

 

The L R vacuum canisters have electrical wiring attached to them and all of it can go EXCEPT the resistance wire which powers the coil. That can be cut out of the blue cover and must be put back in place.

Ok. I will most likely start with the vacuum components and smog crap. From there i'll try to build the courage up to touch the electrical.

 

Thanks for the help/ photos/ further descriptions!