Can't get Holley to idle down with screw - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 07-10-2010, 04:30 AM
Member
 
Join Date: Aug 2003
Posts: 137
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Can't get Holley to idle down with screw

I have a 4100 series vaccumn secondary with electric choke Holley carb on a factory quadrajet intake with a alumiumn adadpter plate to make the holley fit.It is on a 350 chevy in my 67 C-10 truck.I just got it running and i can't get the Holley to idle down.I have the idle screw on the left side of carb.backed all the way out and it still idles too high.I can pull foward on the linkage real hard and it will idle down but this hard pull force can't be corrected with a stronger spring.The 12VDC is not connected to electric choke yet.Also i should know this but which vaccumn port top or bottom does vaccumn advance on distributor usually connect to?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-10-2010, 04:49 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
More than likely it has a vacuum leak around the adapter. My best advice is either get a Quadrajet or a aftermarket intake, the best place for a adapter is the trash, they disrupt the vacuum signal and cause the intake to act as if it`s a open plane, each cylinder is pulling off the carbs entire mass which kills low end power in favor of top end power. If you can`t get the throttle to fully return then check the throttle cable, if it`s on disconnect it, if the car idles correctly afterwards then the cable needs adjusted. Either way, I`d still get rid of the adapter.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-10-2010, 04:49 AM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,930
Wiki Edits: 5

Thanks: 22
Thanked 287 Times in 226 Posts
Is your timing too far advanced?.......Are all the vacuum lines hooked up or capped?

Either of these will cause the high idle
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-10-2010, 05:12 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by shockers69
I have a 4100 series vaccumn secondary with electric choke Holley carb on a factory quadrajet intake with a alumiumn adadpter plate to make the holley fit.It is on a 350 chevy in my 67 C-10 truck.I just got it running and i can't get the Holley to idle down.I have the idle screw on the left side of carb.backed all the way out and it still idles too high.I can pull foward on the linkage real hard and it will idle down but this hard pull force can't be corrected with a stronger spring.The 12VDC is not connected to electric choke yet.Also i should know this but which vaccumn port top or bottom does vaccumn advance on distributor usually connect to?
Look on the choke side of the carb- the fast idle cam is likely hanging the linkage open too far.

Check to see if the linkage on the driver side is actually contacting the curb idle screw- if it isn't, look on the choke side of the carb for the fast idle cam and move it out of the way to allow the carb to isle down.

AFA the vacuum port to use, this depends on if you want to use manifold or ported vacuum for the vacuum advance. Do a search for the pro's and con's of using either/or.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-10-2010, 05:15 AM
Registered User
 
Last photo:
Join Date: Jan 2009
Location: Springfield, MO
Age: 29
Posts: 1,108
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
Theres a hole in the back of the carb (atleast I think it does) and if there is no plug in it then it is a BIG vacuum leak. In later years the trucks brake booster got its vacuum from the back of the carb (or adapter). In earlier years, such as your 67, if they had power brakes at all, they got their vacuum from the back of the intake instead. If you hooked the booster up to the intake and didnt plug the back of the carb then id say thats your issue.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-10-2010, 06:15 AM
Irelands child's Avatar
Registered User
 
Last wiki edit: Ford engine specifications Last photo:
Join Date: Jan 2005
Location: Upstate New York
Posts: 4,932
Wiki Edits: 8

Thanks: 16
Thanked 216 Times in 194 Posts
All good suggestions above and I'll add one more to look at if everything else checks out and that is with everything disconnected, will the throttle plates completely close. They are connected to the throttle shaft with a couple of brass screws and if it's a new or especially a rebuilt carb, may not close completely. Many years ago I had a brand new 3310 that had that problem. Primaries and secondaries can have this problem
__________________
Irelands child
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-10-2010, 06:37 AM
sqzbox's Avatar
My pipes are my music
 
Last photo:
Join Date: Sep 2009
Location: indiana
Age: 64
Posts: 2,938
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
To answer your question, the port on the primary metering plate on the passenger side it ported/timed vacuum that should have 0 vacuum at idle. Everything else is full time vacuum.
Like colbat says, check the fast idle adj. screw on the passenger side of the carb.
Also, I would look into replacing the intake with an Edelbrock performer intake as you will never reach the full potential of the holley on your engine with the adapter. The adapter was made to install other brands of carburetors on the spredbore intake not for performance. Your engine will probably loose performance over the quad.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-10-2010, 06:56 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Only thing, the 4100 doesn't have a metering plate like a 4150/4160.

Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-10-2010, 08:54 AM
sqzbox's Avatar
My pipes are my music
 
Last photo:
Join Date: Sep 2009
Location: indiana
Age: 64
Posts: 2,938
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Maybe I ought to just stick with the mouse and keep my fingers off the keyboard. All I do is keep getting myself into trouble.
Man that's one ugly looking holley. Is that just a replacement 4 barrel? I do see the fast idle adj. screw but not the ported vacuum connection. After looking at it I'm even more convinced the fast idle cam is his problem. At least, that's the first thing I would check.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 07-10-2010, 09:07 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 9,464
Wiki Edits: 0

Thanks: 29
Thanked 486 Times in 441 Posts
Pic is of a 4100 Autolite carb, I believe. Could it be that the OP has a 4010 Holley?, which has a fairly similar look. They were discontinued by Holley 10-15 years ago due to poor sales and lack of popularity, and have just been resurrected as the Summit brand carb.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 07-10-2010, 09:24 AM
sqzbox's Avatar
My pipes are my music
 
Last photo:
Join Date: Sep 2009
Location: indiana
Age: 64
Posts: 2,938
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Man, I already smashed my other keyboard. Had to drag this old one out of the closet. Please tell me colbalt didn't make a mistake.

Still, no metering block though.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 07-10-2010, 12:26 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by ericnova72
Pic is of a 4100 Autolite carb, I believe. Could it be that the OP has a 4010 Holley?, which has a fairly similar look. They were discontinued by Holley 10-15 years ago due to poor sales and lack of popularity, and have just been resurrected as the Summit brand carb.
All I have to go by is the OP's statement:
Quote:
I have a 4100 series vaccumn secondary with electric choke Holley carb...
A lot of guys call the Motorcraft/Autolite carbs a Holley, but if the OP doesn't know what he has or mistyped the numbers, then I don't know.

But either way- no metering blocks.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 07-10-2010, 12:35 PM
sqzbox's Avatar
My pipes are my music
 
Last photo:
Join Date: Sep 2009
Location: indiana
Age: 64
Posts: 2,938
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Resurrected by summit might explain why Holley isn't wrote all over it. Never seen a holley not marked! That's wierd.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 07-10-2010, 12:50 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Below is the 4011 (spreadbore):



And the Summit squarebore "new" version of the Holley 4010:



You can see the resemblance to the 4100 shown above in post #8. There are some slight differences between the Holley 4010/4011 and the Summit- the float adjustments are in a slightly different location, and the secondary vacuum can is slightly tilted on the Holley compared to the Summit.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 07-10-2010, 01:57 PM
66GMC's Avatar
Get in, sit down, hang on
 

Last journal entry: Cab Removal
Last photo:
Join Date: May 2005
Location: Olds, Alberta Canada
Age: 57
Posts: 2,761
Wiki Edits: 0

Thanks: 32
Thanked 90 Times in 85 Posts
Yep that 4100 series in post #8 is an Autolite carb, not a Holley.

Another popular misconception is that they're "double-pumpers", but they are not. The diaphragm at the rear controls the opening of the secondary throttles. (i.e. "vacuum secondaries" which are similar in function to Holley)

Ford used them prior to about 1968, and I've had a couple of them myself.
The one pictured is missing it triangular Ford ID tag, but the numbers (i.e. C3AF-R) are also stamped into the edge of the base-plate.







From my understanding, there were two versions of this 4100 series as well, based on venturi diameter.
the 1.08" ones were rated at 480 CFM,
the 1.12" ones were rated at 600 CFM.

More Autolite 4100 info available on Mustang Tek

A couple more things, although it's sort of been dicussed already with the "make sure both primary and secondary throttles can be closed completely" comments.

1.) The secondaries have an adjustment screw under the base plate, and it's a common trick to adjust that to get the primary butterflies positioned over the transfer slots.
2.) Some folks will drill a small hole in each of the primary butterflies for the same reason.

Last edited by 66GMC; 07-10-2010 at 02:10 PM. Reason: Ooops 1.12", not 1.02"
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Holley idle circuit baddbob Engine 2 08-19-2007 07:43 AM
Holley idle circuit tuning question curtis73 Engine 25 08-03-2007 12:11 PM
Rich idle on a Holley - what to do? hotrodf1 Engine 11 04-15-2006 10:51 PM
I'm going to make a bonfire out of my car blown69stang Engine 36 08-22-2005 03:36 PM
How to get Holley to idle down shockers69 Engine 7 01-31-2004 02:18 PM


All times are GMT -6. The time now is 02:51 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.