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

High Idle

Thread Tools
 
Search this Thread
 
Old May 29, 2023 | 09:36 AM
Share
  #16  
RH F-350's Avatar
RH F-350
Thread Starter
|
Cross-Country
Joined: Jul 2003
Posts: 96
Likes: 1
No adjustment needed if idle drops to 600/700 rpm when unplugging iac? Thanks
 
Reply
0
Old May 29, 2023 | 12:03 PM
Share
  #17  
R&RFord's Avatar
R&RFord
Fleet Mechanic
10 Year Member
Liked
Loved
Community Favorite
Joined: Aug 2015
Posts: 1,838
Likes: 367
From: Candy Mountain
If the idle dropped appropriately then you should not need to adjust the stop screw.

If the closed TPS value is less than 1v and the signal smoothly progresses as the throttle is opened then the TPS should be good.

That leaves you with a bad IAC, wiring damage or computer problem.
 
Reply
0
Old May 29, 2023 | 02:31 PM
Share
  #18  
RH F-350's Avatar
RH F-350
Thread Starter
|
Cross-Country
Joined: Jul 2003
Posts: 96
Likes: 1
The idle dropped from 1500 down to 600 with iac unplugged. checking tps no increase or decrease,
 
Reply
0
Old May 29, 2023 | 06:40 PM
Share
  #19  
Prototypemech's Avatar
Prototypemech
Logistics Pro
Photoriffic
Shutterbug
Community Builder
Liked
Joined: Nov 2013
Posts: 3,929
Likes: 1,199
From: Mojave, Ca
That means your IAC valve is being commanded 100% open or is shorted to a ground-wire. Since your KOEO and KOER test didn't throw any errors codes for this, it leaks me to believe that your ECU is commanding the IAC valve open. A faulty TPS sensor can do this... I'll do some research and see what else can cause the IAC valve to remain 100% open.
 
Reply
0
Old May 29, 2023 | 06:51 PM
Share
  #20  
Prototypemech's Avatar
Prototypemech
Logistics Pro
Photoriffic
Shutterbug
Community Builder
Liked
Joined: Nov 2013
Posts: 3,929
Likes: 1,199
From: Mojave, Ca
Actually, after reviewing this thread, I don't see anything about you checking codes? Did you check codes as requested in post #2 and #15?
 
Reply
0
Old May 29, 2023 | 07:08 PM
Share
  #21  
R&RFord's Avatar
R&RFord
Fleet Mechanic
10 Year Member
Liked
Loved
Community Favorite
Joined: Aug 2015
Posts: 1,838
Likes: 367
From: Candy Mountain
The TPS signal voltage should change as the throttle body opens and closes. Without TPS data the computer has no idea about throttle position.
 
Reply
0
Old May 30, 2023 | 04:29 PM
Share
  #22  
RH F-350's Avatar
RH F-350
Thread Starter
|
Cross-Country
Joined: Jul 2003
Posts: 96
Likes: 1
Still working on it every chance i get. I'll keep you all posted. Thanks
 
Reply
0
Old Jun 1, 2023 | 05:57 AM
Share
  #23  
RH F-350's Avatar
RH F-350
Thread Starter
|
Cross-Country
Joined: Jul 2003
Posts: 96
Likes: 1
It turned out to be the tps sensor, also 02 sensor is bad going to replace it
. The idle dropped to 850 rpm. Thanks all of you for your help.
 
Reply
1
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ways Ford is LOSING to the Competition

 Joe Kucinski
story-1

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

 Brett Foote
story-2

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

 Verdad Gallardo
story-3

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-4

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-5

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-6

Every 2026 Ford Engine Explained

 Brett Foote
story-7

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-8

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-9

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

 Verdad Gallardo
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
1990 f250 5.8l high idle
liberty2701
1987 - 1996 F150 & Larger F-Series Trucks
6
Jul 6, 2013 04:55 PM
too high idle
smertlich
1987 - 1996 F150 & Larger F-Series Trucks
2
Feb 10, 2011 08:17 AM
nothing fixing a high idle?
79broncojosh
1987 - 1996 F150 & Larger F-Series Trucks
7
Feb 4, 2011 11:28 AM
High Idle RPMs
1987F-150
1987 - 1996 F150 & Larger F-Series Trucks
3
Jun 23, 2005 06:07 PM
High Idle Do I need a new TPS??
davetmd
1987 - 1996 F150 & Larger F-Series Trucks
4
Nov 1, 2004 09:56 PM
Back to Subforum
1987 - 1996 F150 & Larger F-Series Trucks
View Next Unread
95 f150 302 push rods




Advanced Search
Reply Closed Thread Share
Forum Jump

All times are GMT -5. The time now is 08:08 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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