4.2 - What affects idle speed? - Page 2 - JeepForum.com
Reply
 
LinkBack Thread Tools
post #16 of 22 Old 07-19-2012, 07:30 AM
Old4X
Registered User
1990 CJ7 
 
Join Date: Nov 2008
Location: Ga
Posts: 5,145
Quote:
Originally Posted by befumo View Post
But why would this affect idle speed? Seems to be something funky going on. It refuses to fast idle properly as well.. even though it is set to 1700. (Changed it with the EGR valve hose plugged, second cam etc). It will start up to 1700 then start increasing towards 2,000 rpms.

Went through and checked all vacuum hoses today, all good.


re: Manifold heater: Didn't mean to check the operation, but check the mounting for vacuum leaks. These are known to cause intermittent vac leaks, and are rarely checked as they aren't visible without a mirror.

If your carb won't hold a steady idle when warmed and properly adjusted, check the return springs (2), and check the throttle shaft bushings for wear. Worn shaft bushings will cause the throttle to stick partially open at idle when warm.


418 miles on 19 gallons of gas. Can't beat the BBD !
Old4X is offline  
Sponsored Links
Advertisement
 
post #17 of 22 Old 07-19-2012, 10:04 AM
Wrenchtosser
Registered User
1990 YJ Wrangler 
 
Join Date: Jul 2012
Location: Roseburg
Posts: 22
Quote:
Originally Posted by befumo
Not sure what exactly you mean lol. The high idle screw sits on the fast idle cam which sets when you pump the gas before you start it. Then the screws rides up the fast idle cam with the choke, or that is how its supposed to work.

For setting the fast idle go below, its the second cam step up from the bottom by the way. Made that mistake..

http://home.sprynet.com/~dale02/solvac.htm#setting
Great info! Thanks for the picture and the link! Now I have a MUCH better understanding of how that Sol Vac thingie works. Much appreciated!
Wrenchtosser is offline  
post #18 of 22 Old 07-19-2012, 11:46 AM
OregonNBeyond
Registered User
1990 YJ Wrangler 
 
Join Date: Jul 2012
Location: Roseburg
Posts: 28
Thanks Bef, Should have the clutch job done by tomorrow, ugh, so that will be next on the list. Easy by comparison

Don't own a Jeep if you can't turn a wrench :)

Ginger
OregonNBeyond is offline  
post #19 of 22 Old 07-19-2012, 03:54 PM Thread Starter
befumo
Registered User
1989 YJ Wrangler 
 
Join Date: Sep 2008
Posts: 829
Quote:
Originally Posted by Old4X View Post
re: Manifold heater: Didn't mean to check the operation, but check the mounting for vacuum leaks. These are known to cause intermittent vac leaks, and are rarely checked as they aren't visible without a mirror.

If your carb won't hold a steady idle when warmed and properly adjusted, check the return springs (2), and check the throttle shaft bushings for wear. Worn shaft bushings will cause the throttle to stick partially open at idle when warm.
Return springs i am assuming you mean..



This is how the screw sits on the fast idle cam after the normal two pumps of the accelerator before starting.



Starting to run out of ideas here, just manually tested the vacuum choke pull off and it works.

'89 YJ Wrangler - Sold
'95 ZJ Orvis Edition
'89 YJ Islander
befumo is offline  
post #20 of 22 Old 07-19-2012, 03:58 PM
superj
Registered User
1987 YJ Wrangler 
 
Join Date: Mar 2008
Location: corpus christi
Posts: 7,057
i had the return spring problem a lot on my weber 34. the springs just wouldn't pull the accelerator arm back enough every time i let off the gas. sometimes that would and sometimes it would stick open at 1000 rpm. it sucked. i had to put some heavy springs on and hten it was so heavy it made it hard to drive the jeep smoothly. i think it was just because my weber 34 was a crappy knock off of a weber or something. it was new when i got this jeep and it still sucked. i never had an issue like that on any other weber i have ever owned or on any of the motorcraft or holleys i have owned

I don't feel like working on anything, at this time.
superj is offline  
post #21 of 22 Old 07-19-2012, 04:02 PM Thread Starter
befumo
Registered User
1989 YJ Wrangler 
 
Join Date: Sep 2008
Posts: 829
Well i noticed that some people have two springs. Does anyone else run two springs, is this stock or? I guess i will go ahead and try it.

'89 YJ Wrangler - Sold
'95 ZJ Orvis Edition
'89 YJ Islander
befumo is offline  
post #22 of 22 Old 04-24-2013, 11:52 AM
wturner1981
Registered User
1990 YJ Wrangler 
 
Join Date: Mar 2013
Posts: 18
newbe what does nuttered mean .and how are you getting 22mpg im get 13 mpg on 31x10.50
wturner1981 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.



Email Address:
OR

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
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
idle speed newyj YJ Wrangler Technical Forum 5 12-16-2011 10:55 PM
Quick idle speed question - Weber Carb - Speed Screw 2.5 turns in, but 0 vacuum unlucky YJ Wrangler Technical Forum 1 04-22-2011 05:30 PM
What affects Idle Speed? bpr YJ Wrangler Technical Forum 8 10-23-2009 07:57 PM
Idle Speed (Help) xj7124 YJ Wrangler Technical Forum 1 02-11-2006 11:17 PM
Idle Speed? dokken08 YJ Wrangler Technical Forum 3 12-05-2004 08:18 PM

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 Off
Pingbacks are On
Refbacks are On

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