Holley idles too fast - Team Camaro Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old May 9th, 04, 01:28 PM Thread Starter
Senior Tech
 
Join Date: Jan 2000
Location: Maryville,TN
Posts: 100
Question

I need some guidance with a fast idle problem on a Holley 670 Avenger carb on my 350. I am replacing a 750 Edelbrock on top of a Performer RPM manifold. This is a brand new carb that I just installed today, and it idles at about 2400 rpm. The curb idle screw is adjusted all the way out, and I backed off the fast idle screw on the choke also. Even with both screws out, it idles way too fast. The linkage seems to moving freely and not binding.

Any ideas where to begin?

Thanks,
Brian


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
68_SS is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old May 9th, 04, 04:29 PM
Senior Tech
 
Join Date: May 2001
Location: Ashby,MN, USA
Posts: 8,305
Post

doesn't Holley give you some sort of an instruction book? i know my Edelbrock Q-jet came with a really comprehensive book that explained the theory of why a carb works and how to change different things to solve different problems.

you don't plan sincerity.
you have to make it up on the spot.

wanna hear about 20 years ago when i was too smart to know any better?
novaderrik is offline  
post #3 of 10 (permalink) Old May 9th, 04, 05:34 PM
Senior Tech
Don
 
ZZ_430's Avatar
 
Join Date: May 2001
Location: Houston, Texas
Posts: 4,491
Post

The secondaries have a stop too, it's a small screw on the bottom side of the carb.

Normally, new carbs don't need that adjustment, have you checked for vacuum leaks?

Don ~ TC Member #15 ~
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Don't mess with Texas!
ZZ_430 is offline  
 
post #4 of 10 (permalink) Old May 9th, 04, 05:37 PM Thread Starter
Senior Tech
 
Join Date: Jan 2000
Location: Maryville,TN
Posts: 100
Post

It did come with an installation and setup manual, not really troubleshooting. I know I can download some stuff from Holley, but thought I could get some hands on advice as well.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
68_SS is offline  
post #5 of 10 (permalink) Old May 9th, 04, 05:38 PM
Moderator
Bill
 
Join Date: Aug 1998
Location: Waldorf Md. USA
Posts: 3,288
Post

Brian,
SOunds like a vacuum leak. Double check and make sure you plugged all the vacuum fittings on the carb, especially the big one on the back. BTDT [img]smile.gif[/img]

Bill Koustenis
Owner
Advanced Automotive Machine
Waldorf Md
1971 Chevelle "Heavy Chevy" original owner


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BillK is offline  
post #6 of 10 (permalink) Old May 9th, 04, 05:47 PM
Senior Tech
 
Join Date: Mar 2002
Location: Austin, TX, USA
Posts: 5,277
Post

I had the same problem on mine recently. Turned out I hadn't given the linkage enough play to return to idle. What happens if you disconnect the throttle linkage all together? Otherwise I agree with ZZ430DropTop67RS. Check out the secondary stop. Should be between 1 and 2 turns out (your milage may vary). But if you get too far outside of that range I'd bet on a vacuum leak.

Dave
========================
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI
dnult is offline  
post #7 of 10 (permalink) Old May 9th, 04, 05:49 PM
Senior Tech
Steven
 
Join Date: Jan 2001
Location: Raleigh, NC
Posts: 1,046
Post

Some thoughts ... Even if the linkage moves freely does not mean that it is properly adjusted. Disconnect the linkage and start the car. This will either eliminate or confirm a linkage problem. Another thing to consider is the choke adjustment. Some carbs ( not sure about this one ) even have a 2nd adjustment screw on the passenger side that affects choke fast idle. I think you have an electric choke. If so, you need key-switched power and a ground. No power means extended choke engagement ... If choke canister has lean/rich adjustment, lean will make the choke release sooner. Are you using manifold vac for your distributor vacuum advance ? If so, that will kick up the idle by advancing the timing. Lastly, is this a problem with the air cleaner on, off, or both ? If this is a problem with the air cleaner on, you may not have the proper air cleaner for the carb...it may be interfering with linkage or other mechanisms ...
sdtsdt is offline  
post #8 of 10 (permalink) Old May 10th, 04, 02:13 AM Thread Starter
Senior Tech
 
Join Date: Jan 2000
Location: Maryville,TN
Posts: 100
Angry

Thanks for all the suggestions, I will check them out when I get home tonight and post back.
68_SS is offline  
post #9 of 10 (permalink) Old May 12th, 04, 02:46 PM Thread Starter
Senior Tech
 
Join Date: Jan 2000
Location: Maryville,TN
Posts: 100
Post

Well I finally got back to the car tonite and found that it was a linkage problem after all [img]graemlins/clonk.gif[/img]

I took it for a short spin to see what kind of difference it would make going from the 750 Edelbrock to the 670 Holley and was a little surprised. I expected better throttle response, but actually it seems a bit more sluggish.

I need to change out the secondary spring to make them open a little sooner and will play with the timing and see what happens.

Thanks for the help.

Brian


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
68_SS is offline  
post #10 of 10 (permalink) Old May 14th, 04, 09:24 AM
Senior Tech
 
Join Date: Apr 2000
Location: holliston, mass
Posts: 622
Post

one more note..
the idle mixture screws will reduce idle if turned in, and will increase idle if turned out.

Keep on truckin' check that timing first, and then have someone fallow you while you test, to see if there is black smoke when you jump on it or not, this will help you determine weather or not you are overfueling (rich) or underfuling (lean)

John...
68ragtop is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome