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

Need help

Thread Tools
 
Search this Thread
 
Old Jun 9, 2012 | 10:16 AM
  #1  
waterdawg69's Avatar
waterdawg69
Thread Starter
|
New User
Joined: Jun 2012
Posts: 9
Likes: 0
Need help

I have a 1979 ford f-150 302 v8 with 31,000 auto. im having problems with rough idle and it stalling while at idle. The truck ran fine till i put new plugs and wire in. Yesterday i put the plugs and wire in and it ran rough. the plugs where gaped right, but when i pulled the plug wires to see if i could find out anything. The passenger back two plug wires had not changed engine idle at all but others did. it has spark fro wire to plug. recently i have changed plugs,wires, cap, rotor, accel pump, coil, fuel filter, air filer. and egr valve but its a used one the old one that was in it was not holing pressure and the used on i got is smaller but fits and it holds vacuum. thanks for any help!
 
Reply
Old Jun 9, 2012 | 10:47 AM
  #2  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Make sure the EGR valve isn't stuck open at idle; otherwise move on for now. If plugs and one wire are literally the only things that changed between it running fine and running poorly, check the resistance of the wire in question. What did you gap the plugs at?
 
Reply
Old Jun 9, 2012 | 11:12 AM
  #3  
waterdawg69's Avatar
waterdawg69
Thread Starter
|
New User
Joined: Jun 2012
Posts: 9
Likes: 0
how do i tell if the egr valve is stuck open? can u unplug the hose and feel for suction. the gap was set at 0.44, how to i check for resistance on the wires.
 
Reply
Old Jun 9, 2012 | 11:23 AM
  #4  
mark a.'s Avatar
mark a.
Lead Driver
20 Year Member
Photogenic
Joined: Mar 2004
Posts: 8,922
Likes: 153
If it ran fine before you changed the plugs and wires then you probably got bad wires or bad plugs, my bet is the plugs. Put it back the way it was and see what happens. What kind of plugs ? I only use Motor-Craft plugs. I've had Champion dead right out of the box, AC, and Autolite as well are all junk.
 
Reply
Old Jun 9, 2012 | 11:28 AM
  #5  
waterdawg69's Avatar
waterdawg69
Thread Starter
|
New User
Joined: Jun 2012
Posts: 9
Likes: 0
the wire are omni spark and the plugs are ngk v power. I put two of the old ones back in the two cylinders and did not make a diff. the one that came out were autolight 25 .
 
Reply
Old Jun 9, 2012 | 01:22 PM
  #6  
J ballan's Avatar
J ballan
Fleet Mechanic
Joined: Jan 2012
Posts: 1,668
Likes: 13
From: Saskatchewan
If it ran fine before you gave it a tune up and there are two cylinders beside each other not firing sounds like you got the plug wires mixed up? Or did I miss something?
 
Reply
Old Jun 9, 2012 | 01:24 PM
  #7  
mikeo0o0o0's Avatar
mikeo0o0o0
Hotshot
15 Year Member
Liked
Loved
Community Favorite
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
Club FTE Gold Member
Be sure the firing order is right and you didn't switch the two wires on the passenger side, the ones that didn't change the idle.
 
Reply
Old Jun 9, 2012 | 01:28 PM
  #8  
arctic y block's Avatar
arctic y block
Post Fiend
Joined: Sep 2006
Posts: 14,325
Likes: 14
From: Island Southeast Alaska
Yes I say check the plug wire firing order as well
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Every 2026 Ford Engine Explained

 Brett Foote
story-1

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-2

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-3

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-4

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-5

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-6

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-7

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-8

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-9

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
Old Jun 9, 2012 | 01:29 PM
  #9  
VocaTexas's Avatar
VocaTexas
Posting Guru
Joined: Feb 2009
Posts: 1,088
Likes: 4
Originally Posted by mikeo0o0o0
Be sure the firing order is right and you didn't switch the two wires on the passenger side, the ones that didn't change the idle.
I think Mike is right. You've got some plug wires on wrong, otherwise the engine would run differently when you unplug one.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Xtrophy
1987 - 1996 F150 & Larger F-Series Trucks
7
Dec 24, 2013 03:43 PM
4604x4
1983 - 2012 Ranger & B-Series
9
May 12, 2013 09:00 PM
Dr. Dirt
1973 - 1979 F-100 & Larger F-Series Trucks
11
May 26, 2008 08:06 PM
kbddbd
3.8 & 4.2L V6
3
Aug 28, 2004 11:16 AM
greenpus
1983 - 2012 Ranger & B-Series
6
May 14, 2001 01:34 PM




All times are GMT -5. The time now is 11:19 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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
story-6
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-7
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-8
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-9
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE