what Vacuum line is this?

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
been figuring out whats wrong with my fury. several Vaccum lines have been plugged with screws causing a blevvy of leaks thus the clicking noise and stall. one last one needs to be fixed. this one at the rear of the carb is plugged with a big screw and cut.

IMG_20200626_114127094.jpg


IMG_20200626_114200464.jpg


IMG_20200626_114131793.jpg
 

Mikes5thAve

Well-Known Member
Joined
Mar 3, 2020
Messages
1,375
Reaction score
540
Location
Canada
The big ones go to PCV valve and the charcoal canister. Some years also brake booster, some years brake booster comes off intake manifold.
Check the vacuum hose sticker under the hood.
If the carb isn't original it could be one that isn't needed.
 

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
its an original lean burn equipped car. not sure why this line was cut. can someone point me to the location of where this hose leads to? also what size is this hose? thanks
 

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
one big line goes to the PCV valve. can't figure out where this plugged one goes. as far as i can tell this car has a factory carb. car has been shaking a lot lately. really at a loss as to what is wrong here.

IMG_20200701_130433891.jpg


IMG_20200701_130324919.jpg


this plugged line is located to the left side of the car. one to the right is hooked up to the PCV valve
 

M_Body_Coupe

Well-Known Member
Joined
Aug 19, 2013
Messages
621
Reaction score
293
Location
Windsor, ON, Canada
Well what I see right there in that last pic is a BIG GAPING vac leak. See the 'T' in that line?

So that channels the manifold vacum to your choke pull-off (which is that puck-like pot the run lines to) and usually is also connected to something else that need vac signal. But in your picture it looks like tha end of that 'T' is wide open...so when the car is running you should in fact feel air getting sucked in-there.

Do you know whether that is a Holley 1945 carb?

My '80 FSM 'Engine Performance Manual' book shows the complete carb hookup here...I'll scan and upload the first couple of pics, that should help I think.
 

Mikes5thAve

Well-Known Member
Joined
Mar 3, 2020
Messages
1,375
Reaction score
540
Location
Canada
If it's stock it should either be a Carter BBD or a holley 6280. I don't think it's a BBD with that solenoid sticking out the side.

Like I said in earlier post there should be a sticker under the hood that shows where all the vacuum hoses go. It's either on the hood or the top of the fire wall by the vent. ANy nipple that doesnt' have a hose shown should be blocked off.
 

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
the T you see open came off when i took the air cleaner off. I've put it back together. i'm mainly focused on the hose with the screw in it. by looking at your scan maybe this is the crank case hose? kinda hard to tell. this hose is located under the choke diaphragm. has two hoses at the rear one which goes to the pcv but this one located to the left side of the car is plugged with a screw. i'll look at the underside of the hood and see what it says. car is a 1988 fury if that helps
 
Last edited:

Aspen500

Well-Known Member
Joined
Feb 14, 2015
Messages
7,030
Reaction score
2,759
Location
Rib Mountain, WI
I see there's another port that goes to the PCV valve. It is entirely possible, if this isn't the original carb, that port is unused and needs to be plugged. I'd get an actual vacuum plug instead of a bolt shoved in a hose though.
 
Last edited:

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
think all i need to do is replace some hoses. one that goes to that T is also a bit tough and cracked. i'll see if i can get an actual plug
 

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
upload_2020-7-2_15-39-49.png

this part was also previously plugged. i've put it back together now though
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
A few questions and a few answers.

The first thing was what year car he has, but he answered that with this photo:
Annotation 2020-07-14 202150.png


There were only three carburetors used on 318 2-bbl FMJ's: The Carter BBD, Holley 2280 and 6280. The 6280 is computer controlled along with some BBD's.
He has the Holley 6280, based off of his pictures.

The Holley 1945 is a single barrel used on /6, so not applicable in this case.

This is a picture taken from my '86 Fifth Ave (also showing a Holley 6280). It looks to me that someone changed carburetors at some time and/or changed the intake vacuum tree for the brake booster. I think the former is more correct than the later.
The brake booster, according to my vacuum hose diagram shows to hook up to rear of carburetor in addition to the PCV hose:
20200714_201536c.jpg


if this isn't the original carb, that port is unused and needs to be plugged. I'd get an actual vacuum plug instead of a bolt shoved in a hose though.
I do agree with this statement, Go to parts store and get a rubber (or soft plastic) plug and stop this port the correct way. That hose will split and will cause a large leak sometime in the future (sooner than later).
Rubber Vacuum Plugs.jpg

Plastic Vacuum Plugs.jpg

The port is 11/32” (0.3438”) which is not a common size. 5/16” = 0.3125” and 3/8” = 0.375” (which is a tad too big) are common sizes.

Actually. I would move the PCV hose back to the correct port – but that might not matter.


20200701_130324919.jpg

This picture (green circle) shows the disconnected “vacuum T” that might be the source of running rough. There is a hose going to air cleaner (heated trap door, over drivers side exhaust manifold, that connects to that “T”). When removing the air cleaner, I prefer to disconnect both hoses at the air cleaner. The one mentioned in sentence above, at the air cleaner temp sensor and at the computer. I then plug both with a Phillips or Torx screwdrivers – so engine "could" be ran with air cleaner off (which is hard to do if engine computer was disconnected, as well). That way, I recover my screwdrivers and pretty certain everything is re-hooked up before closing the hood (or what method works for me, anyway).
Another reason I disconnect the hoses at air cleaner/computer, is because heat causes the hoses at carburetor to get hard faster. the hoses at other end stay soft a lot longer (from lack of heat?) - so fewer chances of hose cracking/breaking. It is also faster for me to disconnect/reconnect at both ends.


upload_2020-7-2_15-39-49.png

The yellow arrow is your EGR valve. I would bet (a dollar) your passageways inside of your intake are 100% stopped up from carbon deposits – which would render the EGR valve inoperative, IF the EGR valve has been disconnected for a couple of years or longer.
BudW
 

Mikes5thAve

Well-Known Member
Joined
Mar 3, 2020
Messages
1,375
Reaction score
540
Location
Canada
It looks to me that someone changed carburetors at some time and/or changed the intake vacuum tree for the brake booster. I think the former is more correct than the later.
The brake booster, according to my vacuum hose diagram shows to hook up to rear of carburetor in addition to the PCV hose:
Actually. I would move the PCV hose back to the correct port – but that might not matter.

To avoid confusion his vacuum sticker shows the brake booster coming off the vacuum tree and the PCV hose already hooked up to the proper port. The brake booster location switched back and forth over the years, you'd think they would have kept it consistent when everything else is the same.

This picture (green circle) shows the disconnected “vacuum T” that might be the source of running rough. There is a hose going to air cleaner (heated trap door, over drivers side exhaust manifold, that connects to that “T”). When removing the air cleaner, I prefer to disconnect both hoses at the air cleaner.

He mentioned that one goes to the air cleaner. I also disconnect that hose at the air cleaner when taking it off, mainly because it's easier compared to either digging down to the bottom of the carb or getting it off the barbed T. A golf tee plugs it perfectly without affecting the hose.
 

SonOfaTomP

Well-Known Member
Joined
Jul 22, 2017
Messages
328
Reaction score
105
Location
Baltimore
i've replaced that hose to the tree. it has a minor crack at the bottom. i've had a leaking gas line replaced and i've plugged that port. seems this carb has definitely been replaced but i can't id what exactly it is. car has been rough lately even with my efforts to solve the vacuum issue. issues like shaking and stalling when put in drive. this seems to have all gne away after my last drive so i dunno. i can't seem to find anything out of place other than some old lines with small cracks which i'll soon fix. can't feel any air coming out of them though
 

Mikes5thAve

Well-Known Member
Joined
Mar 3, 2020
Messages
1,375
Reaction score
540
Location
Canada
Yes it looks like it's right to the barbed end. You might have enough hose there to cut the cracked part off.
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
Its not the EGR valve, per se. It is the ports inside of the intake going to the EGR valve that I would bet are stopped up (solid) with carbon.

If you are in a state that requires the EGR valve to function, you might have to remove the cast iron intake and spend a weekend cleaning out the exhaust crossover and EGR ports in intake (unless you are considering converting to an 4-bbl sometime down the road).
If your state/community doesn't check the EGR system for functionality, I would recommend you spend the weekend fishing (or whatever) than spend time and sweat getting greasy over something not really important.

I have worked on some intakes that it takes a punch & hammer and a drill to get those hardened carbon deposits removed (many hours later).
BudW
 
Back
Top