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5/09/2021 8:54 PM  #1


Idle speeder??

Back in the old days I remember cars had a solenoid that upped the idle speed and then let it back off every time the compressor turned on and off. The only ones I've been able to come up with will only do it if you tap the throttle pedal. I don't remember the cars this gadget was on or what it was called. I got one off a vet but it doesn't work as I remember.


70, ragtop 351W/416 stroker Edel Performer heads w pro flow 4, Comp roller 35-421-8. T5
 

5/09/2021 9:57 PM  #2


Re: Idle speeder??

Idle compensator is term I recall.

Last edited by Nos681 (5/09/2021 10:03 PM)

 

5/10/2021 6:21 AM  #3


Re: Idle speeder??

Fast Idle Solenoid is what I call it. I have one on my Holley that is wired into the compressor wire. You can buy them brand new with the mounting bracket.

 

5/10/2021 7:40 AM  #4


Re: Idle speeder??

I never found one that would actually kick hard enough without a little help. So I kind of gave up, but then I started thinking lately about if adding a capacitor would work.
Idle up solenoid used on diesel air compressors or for truck hydraulics would work, but then your going spend a few hundred $.

 

5/10/2021 8:23 AM  #5


Re: Idle speeder??

Try idle speed solenoid.

 

5/10/2021 9:38 PM  #6


Re: Idle speeder??

red351 wrote:

I never found one that would actually kick hard enough without a little help.

None of them have the "strength" to push the throttle lever open. You have to step on the throttle, the solenoid plunger extends and then when you let your foot off the throttle the extended plunger stops the throttle lever from closing completely.
 

 

5/11/2021 8:10 AM  #7


Re: Idle speeder??

As you already stated - the available idle solenoids require that you tap the gas pedal to raise the idle when the compressor kicks on. That works for me, but isn't ideal. Some of the old Autolite 4100 4 barrels had a "Hot Idle Compensator" valve that was activated by a bimetallic strip. When the temp got high enough a tiny valve opens to allow more air into the intake tract raising the idle speed. It is a controlled vacuum leak through the carb. I was thinking that a small solenoid activated valve plumbed in to the intake could accomplish the same thing. When the compressor kicks on, the solenoid would open a valve to raise the idle speed.


 

 

5/11/2021 9:25 AM  #8


Re: Idle speeder??

Kevin197 wrote:

As you already stated - the available idle solenoids require that you tap the gas pedal to raise the idle when the compressor kicks on. That works for me, but isn't ideal. Some of the old Autolite 4100 4 barrels had a "Hot Idle Compensator" valve that was activated by a bimetallic strip. When the temp got high enough a tiny valve opens to allow more air into the intake tract raising the idle speed. It is a controlled vacuum leak through the carb. I was thinking that a small solenoid activated valve plumbed in to the intake could accomplish the same thing. When the compressor kicks on, the solenoid would open a valve to raise the idle speed.

I did try that vacuum leak solenoid thing a few yrs ago. It didn't work well, I guess because the sudden shock and drag from the compressor already started to stall the engine before the leaner fuel mixture reached the cylinders. I even tried to use that air solenoid plumed to 2" round vacuum pot to pull on the throttle. Again that idea did work, because I would need a way to dump the left over vac. between pot and when valve closes to return to a normal idle. I just going to do pedal tap dance till I come up with another worthless brain storm.
 

 

 

5/11/2021 10:00 AM  #9


Re: Idle speeder??

Wouldn't it be feasible to adapt something like a solenoid for a door popper or power lock to this purpose?  It'd be bigger than the "normal" units used on the carbs but should have more than enough force to push the throttle open a bit, give or take how many throttle return springs you have in place.


Founding Member of the Perpetually Bewildered Society
 

5/11/2021 3:51 PM  #10


Re: Idle speeder??

John Ha wrote:

Wouldn't it be feasible to adapt something like a solenoid for a door popper or power lock to this purpose?  It'd be bigger than the "normal" units used on the carbs but should have more than enough force to push the throttle open a bit, give or take how many throttle return springs you have in place.

Popper is just what it is.   30 seconds of applied voltage it goes up in smoke. I know that because I tried, but it did have enough kick.
 

Last edited by red351 (5/11/2021 3:53 PM)

 

5/11/2021 4:28 PM  #11


Re: Idle speeder??

So the idle solenoids wont open the throttle at idle when the A/C cycles on. A blip on the throttle and it holds the idle up till the A/C cycles again. A real pain in the arse. What if the solenoid was on all the time that the A/C was on regardless of compressor on/off. The result would be a fast idle when the compressor is off and just right when it's on. The faster idle would help cooling in stop/go traffic on hot days. 

Last edited by RV6 (5/11/2021 4:29 PM)


Gary Zilik - Pine Junction, Colorado - 67 Coupe, 289-4V, T5
 

5/12/2021 6:26 AM  #12


Re: Idle speeder??

RV6 wrote:

So the idle solenoids wont open the throttle at idle when the A/C cycles on. A blip on the throttle and it holds the idle up till the A/C cycles again. A real pain in the arse. What if the solenoid was on all the time that the A/C was on regardless of compressor on/off. The result would be a fast idle when the compressor is off and just right when it's on. The faster idle would help cooling in stop/go traffic on hot days. 

The problem here is the wife & I have 2 Cleveland's and as soon as they get just a little more gas they want to run thru  traffic lights & stop signs
On the serious note,  I think the cam may be the real problem. Stock cam & A/C and no idle solenoid was never a problem.

 

5/12/2021 11:27 AM  #13


Re: Idle speeder??

red351 wrote:

RV6 wrote:

So the idle solenoids wont open the throttle at idle when the A/C cycles on. A blip on the throttle and it holds the idle up till the A/C cycles again. A real pain in the arse. What if the solenoid was on all the time that the A/C was on regardless of compressor on/off. The result would be a fast idle when the compressor is off and just right when it's on. The faster idle would help cooling in stop/go traffic on hot days. 

The problem here is the wife & I have 2 Cleveland's and as soon as they get just a little more gas they want to run thru  traffic lights & stop signs
On the serious note,  I think the cam may be the real problem. Stock cam & A/C and no idle solenoid was never a problem.

I have the fast solenoid and mounting bracket from Holley. About $100 worth of stuff. Sometimes it kicks the idle up, sometimes I have to blip the throttle to have it kick in. As often as the compressor cycles with the vintage air, the words of MS echo in my ears of bump the idle up in the simmer and live with out it. 

Gary, you're making the case for idling up the carb and saving the money!! 
 


John  -- 67 Mustang Coupe 390 5 speed
 

5/12/2021 2:55 PM  #14


Re: Idle speeder??

red351 wrote:

RV6 wrote:

 

 I think the cam may be the real problem. Stock cam & A/C and no idle solenoid was never a problem.

Sounds like a looser convertor might be the fix!!
6s6
 


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

5/12/2021 3:18 PM  #15


Re: Idle speeder??

Bolted to Floor wrote:

red351 wrote:

RV6 wrote:

So the idle solenoids wont open the throttle at idle when the A/C cycles on. A blip on the throttle and it holds the idle up till the A/C cycles again. A real pain in the arse. What if the solenoid was on all the time that the A/C was on regardless of compressor on/off. The result would be a fast idle when the compressor is off and just right when it's on. The faster idle would help cooling in stop/go traffic on hot days. 

The problem here is the wife & I have 2 Cleveland's and as soon as they get just a little more gas they want to run thru  traffic lights & stop signs
On the serious note,  I think the cam may be the real problem. Stock cam & A/C and no idle solenoid was never a problem.

I have the fast solenoid and mounting bracket from Holley. About $100 worth of stuff. Sometimes it kicks the idle up, sometimes I have to blip the throttle to have it kick in. As often as the compressor cycles with the vintage air, the words of MS echo in my ears of bump the idle up in the simmer and live with out it. 

Gary, you're making the case for idling up the carb and saving the money!! 
 

Doug sent me the fast idle solenoid that is currently installed in the mustang. It works great till the compressor shuts down at idle. A tap of the throttle and she's back to a faster idle with the A/C on.


Gary Zilik - Pine Junction, Colorado - 67 Coupe, 289-4V, T5
 

5/12/2021 5:07 PM  #16


Re: Idle speeder??

6sally6 wrote:

red351 wrote:

RV6 wrote:

 

 I think the cam may be the real problem. Stock cam & A/C and no idle solenoid was never a problem.

Sounds like a looser convertor might be the fix!!

Can't get any looser than a 4sp toploader on the red car
6s6
 

 

 

Board footera


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