Notices
1999 - 2016 Super Duty 1999 to 2016 Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Sponsored by:
Sponsored by: Real Truck

Gasser High Idle Idea

Thread Tools
 
Search this Thread
 
Old Feb 20, 2009 | 12:42 PM
  #1  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Gasser High Idle Idea

I haven't seen any way of doing a high idle in the 2v gas motors. I have an idea, but I don't know how the IAC is actuated. Basically, I think there is a voltage wire to the IAC, this wire has a variable voltage to open and close the IAC to adjust the idle. So interrupt this wire with a relay, 30 to the IAC, 87a to the ECM. Then the coil to a switch. The rub is the 87, provide current at a voltage where it spins the engine to the desired RPM. I don't know how much resistance the IAC should have and what kind of potentiometer (wattage rating) to use to adjust the voltage or if it will require a power supply. Any ideas or input?
 
Reply
Old Feb 20, 2009 | 05:47 PM
  #2  
high ho silver's Avatar
high ho silver
Posting Guru
Joined: Apr 2004
Posts: 1,342
Likes: 0
From: Georgia
Sounds like you know how to build the swiss watch not just tell us what time it is. Wow I'm impressed and don't have a clue what you said other that what the IAC is supposed to be used for but hey.....It could very well work. Let us know.
 
Reply
Old Feb 20, 2009 | 05:53 PM
  #3  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
I'd like to learn what voltages open the IAC how much, and if the ECM senses the load on the wire before I build something. But it's a basic idea to isolate a new power source from the ECM, and with enough current applied at the right voltage, it might adjust the idle up to 1000-1500rpms, maybe even 2k rpms. I can work through some of the circuit, but need a little help in the details.

To learn, I'd have to cut the power wire and read the amperage. It's not something I want to do right now, but maybe someone knows the impedance or amperage/voltage to run the IAC at various positions.
 
Reply
Old Feb 20, 2009 | 07:18 PM
  #4  
rwilimo's Avatar
rwilimo
Fleet Mechanic
Joined: Aug 2005
Posts: 1,339
Likes: 5
From: NJ
While your idea is sound, the pcm would not like this. You will have a service engine light on all the time and you may cause some drivability problems, as the pcm will likely try to adjust to what it interprets as a problem. Let me know if you would like to further discuss this.
 
Reply
Old Feb 20, 2009 | 07:20 PM
  #5  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Yep, I didn't think about the ECM not liking the new RPM set. Thanks.
 
Reply
Old Feb 20, 2009 | 07:27 PM
  #6  
rwilimo's Avatar
rwilimo
Fleet Mechanic
Joined: Aug 2005
Posts: 1,339
Likes: 5
From: NJ
Its not only the unexpected rpm, but the open circuit to the iac. The pcm monitors connections to sensors/outputs and would detect the open circuit.
 
Reply
Old Feb 20, 2009 | 07:59 PM
  #7  
Monsta's Avatar
Monsta
Sit. Stay.
Joined: Oct 2001
Posts: 18,308
Likes: 20
From: Washington State
Club FTE Silver Member

How 'bout a brick on the bottom edge of the gas pedal instead?
 
Reply
Old Feb 20, 2009 | 08:06 PM
  #8  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
The impedence the ECM saw on the IAC was one of my original concerns.

I use a 2x4 or my dewalt drill normally.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-1

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-2

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

 Verdad Gallardo
story-3

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

 Joe Kucinski
story-4

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

 Brett Foote
story-5

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-6

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

 Brett Foote
story-7

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

 Michael S. Palmer
story-8

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

 Verdad Gallardo
story-9

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
Old Feb 20, 2009 | 08:22 PM
  #9  
Sooper-Doodie's Avatar
Sooper-Doodie
Senior User
Joined: Jan 2009
Posts: 419
Likes: 1
How about a high idle motor for a carbed motor. You know, the once that bumps the throttle lever a little to compesate for A/C????? Make up a bracket for it and hook it to a switch placed in the dash..... Should work ok I would think.
 
Reply
Old Feb 20, 2009 | 08:31 PM
  #10  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Actually, Idea #2 is like the first but using the cruise control servo. Same basic principle, apply a voltage to the cruise servo (motor only not the cruise control electronics) to draw the throttle body open. Wiring would be similar, but it would probably require disassembly of the cruise module. 30 to the servo and 87a to the module.
 
Reply
Old Feb 20, 2009 | 08:43 PM
  #11  
tesserra's Avatar
tesserra
Mountain Pass
15 Year Member
Joined: Jan 2008
Posts: 140
Likes: 1
Could you fool the ECM into thinking the motor is still cold? This opens up the IAC and should not upset the ECM too much unless it goes into a richer burning mode. How many temp sensors report back to the ECM? If it is only 1 then it could work.
 
Reply
Old Feb 20, 2009 | 09:09 PM
  #12  
ReAX's Avatar
ReAX
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Cold ECT seems to only be 1000rpm or so. When I get around to doing something with this, I'd like 1500-2000rpms to spin my alt up to a high output range. Then using a pot to control the voltage would let me tune the RPMs a little which is why I was hoping to find a way to integrate one. But to answer your question, yes all you have to do is add resistance. The way I would do that is power the coil of a relay with a switch. 30 goes to the ECM on ECT wire, 87a goes to the ECT and 87 has a resistor inline to the ECT. This would let you throw a switch and change from the ECM reading actual engine coolant temp or your altered engine coolant temp.
 
Reply
Old Feb 21, 2009 | 02:22 AM
  #13  
_Rick_'s Avatar
_Rick_
Elder User
Joined: Dec 2007
Posts: 784
Likes: 1
From: White Rock BC Canaduh
Originally Posted by ReAX
Cold ECT seems to only be 1000rpm or so. When I get around to doing something with this, I'd like 1500-2000rpms to spin my alt up to a high output range. Then using a pot to control the voltage would let me tune the RPMs a little which is why I was hoping to find a way to integrate one. But to answer your question, yes all you have to do is add resistance. The way I would do that is power the coil of a relay with a switch. 30 goes to the ECM on ECT wire, 87a goes to the ECT and 87 has a resistor inline to the ECT. This would let you throw a switch and change from the ECM reading actual engine coolant temp or your altered engine coolant temp.
Getting the idle up on my 6.8 has crossed my mind in the past also. It's been awhile since I was looking over the throttle trying to figure something out, but I remember putting some thought into hooking up a simple old school choke cable assembly. I was concerned with having a BIG pull switch in the cab for it, but I found cool small unit that I liked. I ended up moving onto other projects and lost track of where I saw the small cable switch unit. I have a link for the cable buried in a backup somewhere (I lost my laptop harddrive recently). I'll get to restoring my files soon and will let you know if it's something you might want to look into for your application.
 
Reply
Old Feb 21, 2009 | 08:57 AM
  #14  
tesserra's Avatar
tesserra
Mountain Pass
15 Year Member
Joined: Jan 2008
Posts: 140
Likes: 1
When I had the IAC replaced the mechanic tested it with a something that was hooked up to the code reader outlet in the cab. He was able to change the idle with this device. I didn't notice if changed variably or it was just 1 single higher rpm setting, but it was slick when he did it.
 
Reply
Old Feb 21, 2009 | 09:29 AM
  #15  
rwilimo's Avatar
rwilimo
Fleet Mechanic
Joined: Aug 2005
Posts: 1,339
Likes: 5
From: NJ
Originally Posted by tesserra
When I had the IAC replaced the mechanic tested it with a something that was hooked up to the code reader outlet in the cab. He was able to change the idle with this device. I didn't notice if changed variably or it was just 1 single higher rpm setting, but it was slick when he did it.
This makes me wonder if some kind of programmer could handle the high idle?

Another option is something like this: High-Idlers we use them in limo's sometimes and they get the job done.
 
Reply



All times are GMT -5. The time now is 01:32 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