International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-11-2020, 02:46 PM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
High idle help

I've had an issue with my 401 idling way too high since I bought my truck.
I replaced the intake manifold gasket, replaced valve cover gaskets, replaced carb, carb adapter, and gaskets.
I fixed timing.
It starts right up and runs strong. It idles just a little too fast at start up, but sounds good. The warmer the engine gets, the faster it idles.
I've sprayed all around the carb and intake without any changes.
I've replaced main vacuum lines and plugged unused ports.

What do you guys suggest I should do/look at next?
Appreciate any help.
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #2  
Old 09-11-2020, 11:24 PM
wiley-moeracing wiley-moeracing is offline
350 Buick
 
Join Date: Feb 15, 2010
Location: arizona
Posts: 1,307
What carb is on it?
Reply With Quote
  #3  
Old 09-12-2020, 06:32 AM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
Edelbrock 1906 avs2 650cfm
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #4  
Old 09-12-2020, 06:44 AM
wiley-moeracing wiley-moeracing is offline
350 Buick
 
Join Date: Feb 15, 2010
Location: arizona
Posts: 1,307
How much higher is the idle? a couple of things come to mind, look at your idle adjustment screws make sure the tips are not broken off and then inspect the inside of the venturi and look at where the idle screws are to see if the holes are ok and not broken out or enlarged( from over tightening it). Then look at your idle screw, where is it set, if you have a vacuum leak and you have to crack the blades open to far you can roll out of the idle circuit. Is the linkage for fast idle out of adjustment? Check the booklet from edelbrock that came with the carb, can be helpful.
Reply With Quote
  #5  
Old 09-12-2020, 10:57 AM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
Quote:
Originally Posted by wiley-moeracing
How much higher is the idle? a couple of things come to mind, look at your idle adjustment screws make sure the tips are not broken off and then inspect the inside of the venturi and look at where the idle screws are to see if the holes are ok and not broken out or enlarged( from over tightening it). Then look at your idle screw, where is it set, if you have a vacuum leak and you have to crack the blades open to far you can roll out of the idle circuit. Is the linkage for fast idle out of adjustment? Check the booklet from edelbrock that came with the carb, can be helpful.


Thanks for your reply. I have the idle speed screw backed out all the way. Idle at cold start is between 900-950. As the engine warms up, it gets closer to 2000 rpm.
It idled way too high before I replaced the carb but I didn't think much of it because it wasn't running right in general.
The fuel pump looks to be newer.... Is it possible it's pushing too much fuel pressure to carb?
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #6  
Old 09-12-2020, 11:09 AM
babywag's Avatar
babywag babywag is offline
out of order
 
Join Date: Jun 08, 2005
Location: Land of froot loops and cukcoo-nuts, CA
Posts: 9,793
verify the throttle cable/linkage/return spring are allowing throttle to close all the way.
seen it several times where a cable wasn't allowing throttle to fully close.
__________________
Tony
Reply With Quote
  #7  
Old 09-12-2020, 09:10 PM
78 WIDETRAC's Avatar
78 WIDETRAC 78 WIDETRAC is offline
327 Rambler
 
Join Date: Aug 19, 2003
Location: Portland, Or
Posts: 632
This is just a shot in the dark, but what about a leak between the intake and block on the backside? It is a pain to spray in an exact spot back there.



The reason I mention this is.... My 79 has a high idle due to a massive vac leak! I can see the front intake rubber gasket is sort of twisted and squished out so it has no chance of providing a seal. I personally use RTV not the provided rubber seals, so this is on the list to change now that I got it running.




All bad info.... See post #9 My apologies

Last edited by 78 WIDETRAC : 09-13-2020 at 01:24 PM.
Reply With Quote
  #8  
Old 09-13-2020, 06:48 AM
wiley-moeracing wiley-moeracing is offline
350 Buick
 
Join Date: Feb 15, 2010
Location: arizona
Posts: 1,307
The idle screws should only be backed out 2-3 turns from seated position on both sides, not all the way out, which will cause the idle speed to be high.
Reply With Quote
  #9  
Old 09-13-2020, 12:28 PM
Ristow Ristow is offline
 
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 17,261
Quote:
Originally Posted by 78 WIDETRAC
s a high idle due to a massive vac leak! I can see the front intake rubber gasket is sort of twisted and squished out so it has no chance of providing a seal. I personally use RTV not the provided rubber seals, so this is on the list to change now that I got it running.






this is not a vacuum leak. that end seal is an oil seal not a vacuum seal.
__________________
Quote:
Originally Posted by Hankrod
Ristows right.................again,




Quote:
Originally Posted by Fasts79Chief
... like the little 'you know what's' that you are.




Quote:
Originally Posted by Fasts79Chief
I LOVE how Ristow has stolen my comment about him ... "Quoted" it ... and made himself famous for being an ***hole to people. Hahahahahahahahahha!


→ Where the kids hang out...

fsjbuilder.org come for the mindless chat,stay for the hand drawn emoticons.

It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...
Reply With Quote
  #10  
Old 09-13-2020, 12:36 PM
78 WIDETRAC's Avatar
78 WIDETRAC 78 WIDETRAC is offline
327 Rambler
 
Join Date: Aug 19, 2003
Location: Portland, Or
Posts: 632
Quote:
Originally Posted by Ristow
this is not a vacuum leak. that end seal is an oil seal not a vacuum seal.




I'm not sure why I thought that. Thanks for pointing that out. The entire motor would be on vacuum if that were the case. You probably typed what others were thinking when they read my comment.
Reply With Quote
  #11  
Old 09-13-2020, 08:35 PM
ckiczenski's Avatar
ckiczenski ckiczenski is offline
230 Tornado
 
Join Date: Apr 21, 2014
Location: Missouri
Posts: 6
I know you said you tried spraying break cleaner around gaskets to see a change in idle & find a vacuum leak. But I would really recommend throwing a vacuum gauge on it and seeing what it reads at idle. They are relatively cheap if you don't have one. It really sounds like a vacuum leak somewhere to me
Reply With Quote
  #12  
Old 09-14-2020, 06:20 PM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
I have the idle mixture screws just over 2 turns out.
I ordered a vacuum gauge, some vacuum connectors and a fuel pressure regulator.
I'll report back with what I find.
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #13  
Old 09-16-2020, 05:31 PM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
Quote:
Originally Posted by babywag
verify the throttle cable/linkage/return spring are allowing throttle to close all the way.
seen it several times where a cable wasn't allowing throttle to fully close.

That was it!


I believe I have the timing and carb settings pretty good. Starts right up idles right around 900. Manifold vacuum is right around 19hg. Sounds good when I hit the throttle.

Now it doesn't want to go into gear. Sounds like it's stuck in-between gears and grinds when I put it back in park. Didn't have this issue before I don't know if I messed something up when I was cleaning up vacuum lines or if it's just bad timing. Finally get it running good and it doesn't want to move. Haha
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
  #14  
Old 09-16-2020, 06:29 PM
rang-a-stang's Avatar
rang-a-stang rang-a-stang is offline
Administrator
 
Join Date: Oct 31, 2016
Location: Camarillo, CA
Posts: 3,775
Mine does that when the transfer case shifter is in neutral. Make sure you are in normal or Low...
__________________
79 Cherokee Chief (passed CA smog check Sept 2020)
(Cherokee Build Thread)
11 Nissan Pathfinder Silver Edition 4x4
09 Mazdaspeed3 Grand Touring
Reply With Quote
  #15  
Old 09-18-2020, 11:27 AM
brentwood brentwood is offline
232 I6
 
Join Date: Oct 01, 2015
Location: Mullica River, NJ
Posts: 136
You guys are awesome. Really appreciate the help. Going to fine tune it. Then start prepping for raptor liner
__________________
1982 Wagoneer w/258, Rusty's 4in spring lift, motorcraft 2100, 32x11.5x15 bfg's *sold*

1972 J4000 Chevy 350, th350, divorced Dana 20, Holley carb, alcan 4in springs, 35in BFGs on 15in slots

1978 J10 golden eagle w/Levis interior, 401and th400, Edelbrock avs2, 32x11.5 falken rubitreks on stock golden eagle wheels
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Ported or manifold vacuum to the Dizzy? rang-a-stang General FSJ Discussion 20 02-15-2017 03:21 PM
Recent high idle issues hmmm crazyspoons General FSJ Tech 3 12-14-2011 11:35 PM
High idle not wanting to kick down Scott General FSJ Tech 5 05-04-2005 05:38 AM
High speed idle sticking? Mike111 General FSJ Tech 3 12-05-2003 07:13 PM
Idle speed too high Dan General FSJ Tech 13 09-18-2001 05:00 AM


All times are GMT -6. The time now is 07:54 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
corner corner