Ford Truck Enthusiasts Forums

Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

91 4.9 running rich

Thread Tools
 
Search this Thread
 
Old Mar 26, 2016 | 12:35 PM
Share
  #1  
gearhead5's Avatar
gearhead5
Thread Starter
|
New User
Joined: Mar 2016
Posts: 16
Likes: 0
91 4.9 running rich
Have a 91 f150 with a 300 that runs rich. it runs rough/hesitates, idles rough/won't idle. I created a vacuum Leak by pulling a vacuum line off and that makes it run pretty good. replaced MAP and temp censors. Also it shifts hard, and pulling vac line off helped with that as well
 
Reply
0
Old Mar 26, 2016 | 12:39 PM
Share
  #2  
bashby's Avatar
bashby
Post Fiend
Joined: Nov 2005
Posts: 7,437
Likes: 4
From: Charles Town, W bygod Va
Did you check codes?
 
Reply
0
Old Mar 26, 2016 | 02:16 PM
Share
  #3  
gearhead5's Avatar
gearhead5
Thread Starter
|
New User
Joined: Mar 2016
Posts: 16
Likes: 0
I haven't but the check engine light is not on
 
Reply
0
Old Mar 26, 2016 | 04:49 PM
Share
  #4  
timbersteel's Avatar
timbersteel
Logistics Pro
Joined: Mar 2005
Posts: 4,698
Likes: 47
From: Mexico, Missouri
Check fuel psi.

Remove vacuum line from fuel pressure regulator and see if fuel is visible. If the diaphragm is ruptured, then it would pull fuel into the intake.
 
Reply
0
Old Mar 26, 2016 | 05:19 PM
Share
  #5  
Conanski's Avatar
Conanski
FTE Legend
15 Year Member
Photogenic
Photoriffic
Community Builder
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Pull codes and measure fuel, post up the results you get.
 
Reply
0
Old Mar 26, 2016 | 07:16 PM
Share
  #6  
gearhead5's Avatar
gearhead5
Thread Starter
|
New User
Joined: Mar 2016
Posts: 16
Likes: 0
Replaced fuel pump recently didn't change anything, have checked pressure regulator already, I'll pull the codes on Monday I'm at my in-laws for the weekend
 
Reply
0
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
1996 5.8 running rich
littleplumbbob
1987 - 1996 F150 & Larger F-Series Trucks
10
Jul 9, 2012 05:05 AM
300 will not stay running
cbatesplants
1987 - 1996 F150 & Larger F-Series Trucks
4
Sep 20, 2010 11:57 AM
Couple FPR and Vacuum Questions
tobyw
1987 - 1996 F150 & Larger F-Series Trucks
1
Nov 14, 2007 10:46 AM
fuel regulator question
tn terry t
1987 - 1996 F150 & Larger F-Series Trucks
5
Oct 22, 2007 10:06 PM
Non-idling 1987 F-150
matt87
1987 - 1996 F150 & Larger F-Series Trucks
19
Jul 1, 2004 09:26 AM
Back to Subforum
1987 - 1996 F150 & Larger F-Series Trucks
View Next Unread
Need help from the noise/vibration detectives




Advanced Search
Reply Closed Thread Share
Forum Jump

All times are GMT -5. The time now is 02:35 AM.

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

Slideshow: Top 10 Ford truck tragedies.

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


VIEW MORE
story-6
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-7
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-8
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
story-9
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE