Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

Missing Vacuum Lines

Thread Tools
 
Search this Thread
 
Old Mar 24, 2021 | 10:28 AM
  #1  
Stephen Comer's Avatar
Stephen Comer
Thread Starter
|
New User
Joined: Mar 2021
Posts: 12
Likes: 0
Missing Vacuum Lines

2 days ago I purchased a truck for a father / daughter project. I'm excited for this forum and appreciate the years of experience and knowledge you all bring to the table.
1978 F150
351
Manual Transmission
4x4

The truck won't idle. Once it's up and running it's ok... not the best, but runs. Once you stop, it dies if you don't feather the gas. I'm starting with vacuum hoses that are missing. Can anyone connect the dots for me on these missing hoses? Or, if you can post a picture of your engine with the correct hoses, I can figure it out from there. Thank you!!!




 
Reply
Old Mar 24, 2021 | 11:28 AM
  #2  
mwoj's Avatar
mwoj
Laughing Gas
10 Year Member
Liked
Loved
Community Favorite
Joined: May 2015
Posts: 932
Likes: 394
From: Port Orchard, WA
#1 Not sure

#2 Opens/closes the flap in the air cleaner. When the truck is cold it’s shut and gets hot air from around the exhaust manifold. When it’s warm it opens and draws cool air in. I think it should be connected to the temp switch I talk about in #3.

#3 is a temperature activated switch. When the engine reaches temp, that switch should allow vacuum from manifold to open the EGR valve (#5).

#4 is a vacuum canister. I’m pretty sure it provided a “reserve of vacuum” if you will.

#5 Is the EGR valve. It circulates some exhaust into the intake to re-burn it for emissions reasons.
 
Reply
Old Mar 24, 2021 | 01:40 PM
  #3  
redroad's Avatar
redroad
Lead Driver
15 Year Member
Liked
Loved
Community Favorite
Joined: Nov 2006
Posts: 5,217
Likes: 506
From: Pa.
Club FTE Gold Member
Is the decal on the drivers side valve cover? if so that will give you the emissions calibration number. With that we can give you the vaccum diagram for your specific motor set up.
also https://www.ford-trucks.com/forums/9...am-needed.html
 
Reply
Old Mar 24, 2021 | 04:19 PM
  #4  
matthewq4b's Avatar
matthewq4b
Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
Ya the vacuum lines are a mess. But it is really simple and nothin like the later trucks.

If you are not in a region that requires under hood or tailpipe inspections you can remove most of it. Let us know if you need to keep the emissions equipment or not.

Right off I can see that the Distributor vacuum line is not hooked up to the correct spot. (See below circled in red where the distributor should be hooked too) '

Start with that. And we can move on once we know if you have to keep the emissions stuff or it can go away.

Then we can get to diagnostics and tuning and sorting the rest of the mess out.



 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kevinv10
1987 - 1996 F150 & Larger F-Series Trucks
2
Aug 30, 2020 05:07 PM
Dennischim
1973 - 1979 F-100 & Larger F-Series Trucks
13
Jun 29, 2019 09:17 PM
benbuilder
1973 - 1979 F-100 & Larger F-Series Trucks
1
Aug 19, 2015 05:45 PM
wintertruck87
1987 - 1996 F150 & Larger F-Series Trucks
28
Nov 21, 2014 10:34 AM
zaaac
1973 - 1979 F-100 & Larger F-Series Trucks
9
Mar 22, 2014 10:59 PM




All times are GMT -5. The time now is 04:22 PM.

story-0
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-1
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-2
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-3
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-4
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
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE