Notices
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

gas tank breather

Thread Tools
 
Search this Thread
 
Old Jul 18, 2003 | 10:39 AM
  #1  
bronco--351W's Avatar
bronco--351W
Thread Starter
|
New User
Joined: Jul 2003
Posts: 20
Likes: 0
gas tank breather

I have a question I have an '81 bronco and I am not using the carbon canister that the vapors from the fuel tank I have the line capped off I was wondering if this will cause a problem......
 
Reply
Old Jul 19, 2003 | 12:50 AM
  #2  
steve83's Avatar
steve83
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
gas tank breather

It'll cause excessive pressure in the gas tank, which is dangerous, and it could spray you in the face with warm gasoline when you pull the cap off. The vapor system doesn't require ANY engine power to operate, so there's no reason not to keep it working right. You can pick up a used carbon canister in a junkyard and hook it up easily.
 
Reply
Old Jul 21, 2003 | 08:11 AM
  #3  
bronco--351W's Avatar
bronco--351W
Thread Starter
|
New User
Joined: Jul 2003
Posts: 20
Likes: 0
gas tank breather

I have a brand new carbon canister I just dont have anywhere to plug the hose into I guess I can use a t and go into the pcv valve but I dont know if that is a good idea
 
Reply
Old Jul 21, 2003 | 08:37 AM
  #4  
steve83's Avatar
steve83
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
gas tank breather

No, it goes to the top of the carb, but there's supposed to be a solenoid valve in there called the "CANister Purge" (CANP). It will look just like this one, and is routed similarly. Check your vacuum map.

 
Reply
Old Jul 21, 2003 | 10:34 AM
  #5  
bronco--351W's Avatar
bronco--351W
Thread Starter
|
New User
Joined: Jul 2003
Posts: 20
Likes: 0
gas tank breather

I have a '81 bronco and the emission sticker under the hood is gone. should I run a line from the canister and t it into the egr vacuum line ?
 
Reply
Old Jul 21, 2003 | 12:53 PM
  #6  
Franklin2's Avatar
Franklin2
Moderator
25 Year Member
Photogenic
Community Builder
Community Influencer
Joined: Jan 2001
Posts: 57,028
Likes: 2,765
From: Virginia
Club FTE Gold Member
gas tank breather

My 351w that I got out of a 79 cougar has a tee in the PCV line that goes to the canister just as you are thinking about doing. It has a short piece of 3/8 rubber line that hooks to the carb, and this is connected to a steel line that goes over to the PCV valve in the oil fill cap. Along the steel line is a small nipple where the canister purge line connects.

This system is non-computerized, so I guess they put a small amount of vacuum on the canister at all times. The later engines with computers have solenoids and the computer picks the best time to purge the canister.
 
Reply
Old Jul 21, 2003 | 01:05 PM
  #7  
bronco--351W's Avatar
bronco--351W
Thread Starter
|
New User
Joined: Jul 2003
Posts: 20
Likes: 0
gas tank breather

I dont know about the idea of the canister hook up to the vacuum port that the pcv valve is connected to because then you would have gas fumes entering into the engine when it is off through the line from the canister
 
Reply
Old Jul 24, 2003 | 10:04 PM
  #8  
steve83's Avatar
steve83
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
gas tank breather

You definitely shouldn't try to tie anything into the EGR vacuum line - you'd ruin the function of the valve. Adding it to the PCV is a much better idea, if it's between the PCV and intake, but the best route is to go back to stock. You can find your sticker here.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

5 BEST / 5 WORST Ford Daily Drivers of the 21st Century

 Joe Kucinski
story-1

10 Fords to Drive Before You Die

 Joe Kucinski
story-2

3 Best / Worst Features Of The 2025+ Ford Expedition

 Brett Foote
story-3

10 Ways Ford is LOSING to the Competition

 Joe Kucinski
story-4

Top 6 Best Deals Available on New Fords & Lincolns Right Now

 Brett Foote
story-5

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-6

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-7

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-8

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-9

Every 2026 Ford Engine Explained

 Brett Foote
Old Jul 28, 2003 | 10:03 AM
  #9  
bronco--351W's Avatar
bronco--351W
Thread Starter
|
New User
Joined: Jul 2003
Posts: 20
Likes: 0
gas tank breather

steve83 the only thing is is that I am not stock I have an edelbrock carb and intake and I am just trying to get this thing to idle fine. one question for anyone does anyone know how many rpms a 351 should idle at? I have it at 1100 and that is the best that I can get it to idle right....as far as the canister I plugged it off at the 3/8 hose but it still gets venting from the gas cap and the canister
 
Reply
Old Aug 3, 2003 | 11:57 AM
  #10  
steve83's Avatar
steve83
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
gas tank breather

Originally posted by steve83
...the best route is to go back to stock.
It's easier to tune the stock carb than the Edelbrock - think how easy it would be to get the truck to run right if you had bought a stock reman from a parts store instead of that "performance" carb that you can't get to perform. ...and you'd have more money in your pocket, too.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
steelholder
1978 - 1996 Big Bronco
3
Aug 28, 2013 07:52 AM
IDIDieselJohn
1987 - 1996 F150 & Larger F-Series Trucks
16
Jan 2, 2013 07:46 PM
Skandocious
1987 - 1996 F150 & Larger F-Series Trucks
8
Jun 21, 2007 10:25 PM
pwcharlie
1978 - 1996 Big Bronco
6
Nov 4, 2006 08:16 PM
Mike Cook
Bronco II
11
May 12, 2004 12:58 PM




All times are GMT -5. The time now is 01:02 AM.

story-0
5 BEST / 5 WORST Ford Daily Drivers of the 21st Century

Slideshow: The 5 best and 5 worst Ford daily drivers of the 21st century.

By Joe Kucinski | 2026-06-23 08:55:01


VIEW MORE
story-1
10 Fords to Drive Before You Die

Slideshow: 10 Fords to drive before you die.

By Joe Kucinski | 2026-06-22 14:29:44


VIEW MORE
story-2
3 Best / Worst Features Of The 2025+ Ford Expedition

The latest Expedition is quite popular, but it certainly isn't perfect.

By Brett Foote | 2026-06-22 14:23:19


VIEW MORE
story-3
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-4
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-5
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-6
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-7
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-8
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-9
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE