1971 carb vacuum port connections... (1 Viewer)

[mathblaster]

I have a '71 fj40 with an '86 2f block. The carb is from '71 and has had a vacuum port added. The dizzy the from '86, so it is vacuum advance and has a high altitude compensator on it. The block has been desmogged as far as I can tell. Also running headers and the '82 2f intake manifold.

For starters I am just trying to figure out the vacuum ports on the carb, where they should connect to and why. Thanks in advance.

 

[Thornton]

I have no idea why they go there but this is the way my 71 is set up and who knows it's probably wrong. A connects to B. For what reason I don't know I'm a carpenter that finds working on these s**t boxes relaxing. D is a port that was added to set the carb up for a vacum advance distributer. A mechanic showed me this 9 yrs ago on my sons 73. I have got no idea what E is for both the stock carb that I have that has been modified for vacum advance and the non USA that I am presently running do not have this. Is C where the vacum hose is suppose to go to the intake?

Buy the way our son and daughter got my wife and I to go to Breckinridge 2 years ago in Jan. and you live in one of the most beautiful places in the country.

Good Luck,
Tom

 

[smerrill]

I will send you some pics of my 71 carb but cannot seem to upload. Send me your emal and I will forward.

 

[Coolerman]

Here are some pics of my recently (by Jim C. )rebuilt 1971 carb.

Pic one shows what used to be a Throttle positioner/Choke breaker, (but is now only a choke breaker due to desmogging) vacuum line (updated from Jim C. post.)

Pic 2 shows the PCV hose connector

Pic 3 shows the nipple connection for the vacuum advance dizzy hose

 

[bsmith123]

71

My 71 looks a little different I think

3 of the lines go to this--do you have this?

course I'm not sure it's hooked up right---I think there is a schematic of the lines in the eng FSM if you check coolermans site

I can get better pics if you need them of the hook up the cylinder has letters where each hose hooks up

I believe it is called the vacuum switching valve

 

[Degnol]

Here are some pics of my recently (by Jim C. )rebuilt 1971 carb.

Pic one shows the Throttle positioner vacuum line

Pic 2 shows the PCV hose connector

Pic 3 shows the nipple connection for the vacuum advance dizzy hose

Isn't that the choke breaker or choke pull-off?

Ed

Ed-It......'K the choke has a fast idle in it, so maybe that is what you are talking about????

 

[Coolerman]

Well, it's actually both. When Jim C. rebuilt mine he removed the Throttle positioner but I can't remember the reason he gave me. The 1974 carb I have still has it. The FSM refers to it as BOTH a Throttle positioner and the Choke Pulling Angle diaphragm.

 

[Degnol]

Well, it's actually both. When Jim C. rebuilt mine he removed the Throttle positioner but I can't remember the reason he gave me. The 1974 carb I have still has it. The FSM refers to it as BOTH a Throttle positioner and the Choke Pulling Angle diaphragm.

Because the choke has a fast idle adjustment associated with it.


Ed

 

[mooker82]

A to B or C (sorry I cant tell which is the vaccum and which is the bigger PCV connector)

D to the distributor

E to the vaccum nipple on the intake.

Thats the way mine is hooked up and it runs.

 

[FJ40Jim]

Because the choke has a fast idle adjustment associated with it.

No.
Because the CB pot has an added piece of linkage on USA carb to actuate a throttle positioner lever. When the carb is desmogged, the TP linkage is discarded, so the pot reverts to it's original function: Choke breaker.

 

[FJ40Jim]

My 71 looks a little different I think

3 of the lines go to this--do you have this?

course I'm not sure it's hooked up right---I think there is a schematic of the lines in the eng FSM if you check coolermans site

I can get better pics if you need them of the hook up the cylinder has letters where each hose hooks up

I believe it is called the vacuum switching valve

This doesn't apply to the OP's truck, since it has a desmogged 2F engine (instead of smogged F) and a vac advance dissy (instead of vac retard).

 

[FJ40Jim]

I have a '71 fj40 with an '86 2f block. The carb is from '71 and has had a vacuum port added. The dizzy the from '86, so it is vacuum advance and has a high altitude compensator on it. The block has been desmogged as far as I can tell. Also running headers and the '82 2f intake manifold.

For starters I am just trying to figure out the vacuum ports on the carb, where they should connect to and why. Thanks in advance.

A is the choke breaker. It connects to manifold vacuum. The best spot for that would be the manifold vacuum fitting located on top of the intake, just in front of the carb. The pic shows a brass pipe plug screwed into the manifold in that location. One could try connecting it to B, which is a much larger canister purge fitting, but that would require some adapting to go from the 3mm CB to the 6mm purge fitting.

C might be the original location of the 2F PCV pipe. It does not appear to be there now. The PCV hose should go from the PCV valve to a central location on the intake manifold.

D is ported vacuum. It connects to a vacuum advance dissy.

E is an emsissions vac fitting. Cap it off.

 

[shafferandy]

Hello all,

I have a similar situation the the above thread and thought it would be good to have all together.

I have a new to me '71 F motor in my truck and my vacuum connections are a little different than above as I only have the lone vacuum connection near the idle mixture screw. Is this the correct location for connection to the distributor? Is this a vac retard distributor?

I have the pcv routed to the large port under the front of the carb and the choke breaker attached to the port under the left side of the carb.

Many thanks for the assistance.
Andy

 

[shafferandy]

Carb info: 9 F 26
June 26 69?

Small Tag: 60201

The carb tag pn correspondes to the same year as the block sn of '71, F349174 but the stamped date seems a little off. Is this correct?

Advance does rotate CW when vacuum is pulled. Answered my question from above, vacuum retard. So I will cap the port pictured above the mixture screw.

 

[FJ40Jim]

Looks like a '79 replacement carb.

The fitting above the idle mix screw is not a ported vac fitting for a distributor. Just cap it off.

And you are correct, that is a stock 71 vac retard dissy. Don't connect it to vaccum. Just set base timing to 10° & drive it.

 

[shafferandy]

Thanks!

 

[shafferandy]

The truck is running great with the above changes, thanks again.

Other question I have is there is no center bolt in the carb for the air cleaner. Does this correspond to an early or late carb? Only reason I ask is that I was going to rebuild the carb based in the 60201 tag and wanted to be sure I got the correct kit.

Thanks again,
Andy

 

[FJ40Jim]

That's a stock F carb, no center bolt.

 

[Marleyws]

I am havimg some vaccum problems myslef. Jim we spoke awhile back I live in akron/canton area.
Anyway I have 2f 4sp setup with original aisan carb on my 72. Previous owner capped off a bunch of the vaccum ports and has an original vaccum switching valve on there. Nothing seems right and I cant get it to run right
I switched one of the lines and its already running better.
My question is...
Can I get tid of this valve box? Any idea what the po intentions where?
Should I just follow the steps in this thread to get me rolling?

 

[Marleyws]

Here are some pictures hopefully you can help