**Sorry, couldn't get pics to work right, so I put links to my Google Pics. Should just click to see the pic. Thanks!!**

Ok, so this is my first post on FTE. I purchased a 1974 F100 360FE/C6 a few weeks ago. I have been searching the forum and found LOTS of helpful information for some of my projects. Thanks for that! But, I have searched and scoured and can't seem to get a straight answer on some vacuum connections on my carburetor. I hope someone here can help. I have found several different vacuum diagrams and none seem to be for my engine. Or . . . I don't know how to read them. Which is possible. I am no mechanic, just know enough to get myself in trouble. When I bought the truck, PO said the carb needed rebuild/replace. After driving, I agreed. I went with replace because I got it cheap enough and don't know how to rebuild myself (would have to pay someone). I got a rebuilt Motorcraft 2bbl from National Carburetors. First issue . . . I didn't notice this until I installed the new carb, but there is an additional vacuum port on the back (see picture). I just left it capped. Anyone know what this is about?

https://docs.google.com/file/d/0BzWb...it?usp=sharing

Secondly, The other vacuum lines may be improper according to some other posts I have read. One leads from the front passenger side of the carb to the distributor advance. And one from the front driver side to a Vac Tree that is attached to the upper radiator hose/thermostat housing.

https://docs.google.com/file/d/0BzWb...it?usp=sharing
https://docs.google.com/file/d/0BzWb...it?usp=sharing

From the tree, one line goes to tranny and the other to a large vac port on the back of the engine (to the left and behind the choke).

https://docs.google.com/file/d/0BzWb...it?usp=sharing

From this connection large line goes to brake booster, 1 small line to the front tree pictured, and the other to the vac canister on the driver fender.

There is also an unused vac port/tree on the front of the engine back and left from the distributor. It currently has nothing hooked to it and I have not felt any vacuum on it.

https://docs.google.com/file/d/0BzWb...it?usp=sharing

The last vac port on carb on the upper passenger side of carb goes to EGR Valve Vac Solenoid.
https://docs.google.com/file/d/0BzWb...it?usp=sharing

The only other vac connection to the carb is a large metal line from the passenger side valve cover.

I know that this is a lot of information, but I really couldn't explain it any simpler. If anyone can verify any of these connections are correct or can shed any light on correct configuration that would be AWESOME!

I have replaced all the plugs and wires, the carburetor, ignition coil, and a few other minor things. I am only getting 5 mpg. I know these engines aren't known for their economy . . . but 5?!? I thought maybe this vacuum stuff may be the problem. The timing is set and the carb doesn't appear to be rich/lean.

Thanks in advance everyone!!

 

To start with, in the last picture, the hook-up is incorrect.
The line that goes from the carb's air horn does not go to the egr valve. That carb port is the air intake for the automatic choke. There should be a short rubber hose that connects to a steel line that goes to the rear of the passenger side exhust manifold. From there, there is another steel line that connects to the thermostatic spring on the passenger side of the carb.
I'll see if I can dig up the vacuum diagrams and post them in a few minutes.

 

I'm not near a scanner so these are pictures of the pages from the Ford emissions manual.
A couple of things. First, most C6's have had the dual diaphragm modulator replaced by the single diaphragm. If that's the case with yours, the single vacuum line goes to the same vacuum T where the brake booster is connected and just plug the other line.
In your first picture just leave the extra vacuum port capped.

 

Thanks Mike, maybe you can help clear this up. . .
I have read LOTS of different threads regarding chokes on the forum. I have looked and looked for these climatic choke tubes. I have one that is just laying against the exhaust manifold. It is attached to the bottom of the choke. There is a hole there where it is, but only one, not two. The end of the tube is tapered like it belongs in the hole, but it won't fit. And, it doesn't explain not having a second hole (or tube) that returns to the air horn on the carb. The choke functions, which could be because the electric portion (I understand it is electric assisted). Does anyone have a pic of the location on the exhaust manifold where this stuff supposedly hooks up on a 360?? I couldn't be any more confused by this!! Why the hell would the PO have hooked the EGR to that if it is not vacuum??

 

The 360's right (passenger side) manifold should have two holes in it, not one.
The larger rear hole goes to the carb. The smaller front hole goes to the choke thermostat.

 

Also, I would leave the vacuum advanced hooked up like you have it. It's doubtful the solenoid, ambient temp sensor and wiring are still there.

 

I think you will learn rather quickly that one of the worst possible things that could happen to our trucks is a "previous owner".

 

NO CRAP on the PO thing!! Shade tree folks just hooking things to whatever they wanted instead of fixing the broken part.

Anyway, Mike, you have been a HUGE help so far. I am slowly getting the vac stuff sorted out.

Unfortunaltely, I still have a few questions if anyone wants to keep helping me . . . and I apologize in advance, I apparently just can't look at the paper, then the truck and put it together on a few things.

First, I understand the vacuum advance. I will leave that as is.

Second, the EGR port side . . . here goes:
Is the temperature controlled vac valve the one on my thermostat housing? Or the one not being used on the manifold? The thermostat housing makes sense - but the pic looks like it should be on a valve like the one for the heater hose. And, the valve on my thermostat housing has three hookups . . . the pic shows only two. One to the carb and one to the T for the Tranny and EGR Valve. Any thoughts on that would be great!

Third, Just making sure I understand correctly, if the transmission only has one vac line, it should be hooked to the big vac valve where the brake booster is. Which means the "T" between the temp controlled valve and the EGR would be eliminated (making a straight run from valve to EGR)?

And finally, the delay valve for the EGR. I don't see one anywhere right off hand. Do I need to procure one? Or just hook the solenoid direct?

Maybe I won't come up with any more questions. But I doubt it.

Thanks!!

 

On the tranny, you don't need to splice into the line for the brake booster. What I was trying to say (poorly) is that the trans line gets hooked to manifold vacuum, not a ported vacuum source, and the easiest way is to just hook the line to the same vacuum source as the power brake hose. This is how the factory did it.
As for the delay valve, there should be one in the circuit. You should still be able to get them from NAPA or others, I know LMC lists them. Rockauto also has them.

 

What I would do on the EGR is run a line from the vacuum port on the carb, through the ported vacuum switch to the delay valve, then to the egr valve. I would remove the three port vacuum switch on the thermostat housing and plug it with a pipe plug, just to clean things up. Use the ported vacuum switch that's in the intake manifold.

As for questions, don't worry. Feel free to ask any and all questions you want. That's how you learn.

 

Awesome, I think I have got most of it figured out. Unfortunately its raining pretty good here in Central AL, so it may be Tuesday before I can mess with it. Thanks for all the help Mike!