Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 02-17-2021, 10:36 AM   #1
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Arrow Can't get engine to idle down

After a decent amount of work I successfully put the engine in and got it hooked up. When I bought my late 31 tudor it came with and extra whats supposed to be a rebuilt model a engine. However, upon starting it up it revs up to what seems like full throttle. Once running if the choke is pulled out it will lower the rpms until finally it will kill the engine once its fully pulled out. I took out the carb and opened it to adjust the float to the correct distance from the machined edge. Checked valves and saw they were not stuck, then lubricated them to make sure of no problems.
I'm still learning as much as I can and just don't understand what could be the problem. Sucking in air somewhere? Fuel issue?
Thanks, Luke.
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 10:49 AM   #2
Big hammer
Senior Member
 
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,114
Default Re: Can't get engine to idle down

Disconnect the linkage from the carburetor and see if the throttle closes! You may have bent the linkage removing/ installing your engine. You could hold the arm on the carburetor closed with a spring and start it up adjust the carburetor idle.
__________________
Don't force it with a little hammer tap, tap, tap
get a bigger hammer tap done
Big hammer is online now   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 02-17-2021, 10:50 AM   #3
Ed in Maine
Senior Member
 
Join Date: May 2010
Location: Washington Cty., ME or Flagler Cty., FL
Posts: 1,106
Default Re: Can't get engine to idle down

Hello Luke, if your engine is running to high at idle position, it means that the throttle plate at the outlet of the carb is not closed, allowing gas to flow from the main jet into the engine. The throttle plate should be almost closed which forces the Idle jet to be the only jet putting fuel into the engine. Note that you should back out the idle speed screw to get the throttle plate closed. Ed
Ed in Maine is offline   Reply With Quote
Old 02-17-2021, 10:55 AM   #4
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,011
Default Re: Can't get engine to idle down

W/the idle adjustment screw backed out, check that the throttle plate closes all the way.
__________________
If you don't hear a rumor by 10 AM, start one!.
Got my education out behind the barn!
katy is offline   Reply With Quote
Old 02-17-2021, 11:01 AM   #5
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Default Re: Can't get engine to idle down

I forgot to mention, I disconnected the linkage already and checked the throttle plate and know that it does moves and had a buddy close it by hand and it still is basically full throttle. As well I have backed the idle screw back until it is almost about to fall out with no luck at dropping the rpms

Last edited by Lukes31a; 02-17-2021 at 11:03 AM. Reason: Forgot to add some information
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 11:17 AM   #6
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Default Re: Can't get engine to idle down

Sponsored Links (Register now to hide all advertisements)
Due to my accelerator return spring being broken the linkage isn't hooked up I have a buddy that sits and holds the throttle by hand. Even with the throttle closed all the way it still is in high rpms.
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 11:41 AM   #7
Will N
Senior Member
 
Will N's Avatar
 
Join Date: Jul 2010
Location: Pennsylvania
Posts: 1,096
Default Re: Can't get engine to idle down

Quote:
Originally Posted by Lukes31a View Post
I forgot to mention, I disconnected the linkage already and checked the throttle plate and know that it does moves and had a buddy close it by hand and it still is basically full throttle. As well I have backed the idle screw back until it is almost about to fall out with no luck at dropping the rpms
This makes no sense. It's not possible for the throttle plate to be closed and to have the engine running at full throttle. Does your friend know which way to turn the throttle to close it versus opening it? I'm with BigHammer on this. The linkage is bent, preventing the throttle from closing.
Will N is offline   Reply With Quote
Old 02-17-2021, 11:44 AM   #8
Y-Blockhead
Senior Member
 
Y-Blockhead's Avatar
 
Join Date: Jul 2011
Location: Redondo Beach, CA
Posts: 5,817
Default Re: Can't get engine to idle down

Check for vacuum/air leaks. I recently had a carburetor (a brand new Zenith, no less!!) with excessive throttle shaft clearance that I was having high idle problems with. An oversize shaft cured the problem.

Check all intake gaskets also.

After thought; Check your plugs. Mine were white it was running so lean from above mentioned air leak. This will confirm you have an air leak somewhere.

Last edited by Y-Blockhead; 02-17-2021 at 11:50 AM.
Y-Blockhead is offline   Reply With Quote
Old 02-17-2021, 11:58 AM   #9
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Default Re: Can't get engine to idle down

Quote:
Originally Posted by Y-Blockhead View Post
Check for vacuum/air leaks. I recently had a carburetor (a brand new Zenith, no less!!) with excessive throttle shaft clearance that I was having high idle problems with. An oversize shaft cured the problem.

Check all intake gaskets also.

After thought; Check your plugs. Mine were white it was running so lean from above mentioned air leak. This will confirm you have an air leak somewhere.
When I get back on it tonight ill look for air leaks, as far as my plugs go they're about the opposite. They're pretty blackened.
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 12:54 PM   #10
Dan Partain
Senior Member
 
Dan Partain's Avatar
 
Join Date: May 2010
Location: Hangtown, CA
Posts: 556
Default Re: Can't get engine to idle down

Crazy question, but did you check the carb to make sure there is a throttle plate on the arm your friend is turning? If so, take a look at it and see if it closes completely. I don't see how it can run full throttle if the throttle plate is in place and fully closed.
Dan Partain is offline   Reply With Quote
Old 02-17-2021, 01:41 PM   #11
31Tudor
Senior Member
 
31Tudor's Avatar
 
Join Date: May 2010
Location: North Carolina
Posts: 611
Default Re: Can't get engine to idle down

Two thoughts:
1. May be the dumb one, but there are two plates, the throttle and the choke. Be sure they both close and open. Choke open and throttle closed.
2. The throttle plate has a bevel cut in it to thoroughly close. It will go on both ways, but not close tight if it is put on backwards (upside down). Look at the throttle plate from the top of the carb and be sure the bevel is turned the right way and it it closing completely.
31Tudor is offline   Reply With Quote
Old 02-17-2021, 01:56 PM   #12
wwirz
Senior Member
 
Join Date: May 2020
Location: Corning NY
Posts: 243
Default Re: Can't get engine to idle down

I would be checking for:

Throttle plate not closed
Linkage bent preventing the throttle plate from closing
Idle adjust screw not properly adjusted.
wwirz is offline   Reply With Quote
Old 02-17-2021, 02:10 PM   #13
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Default Re: Can't get engine to idle down

Alright ill pull the carb tonight and do some looking around and take in all your suggestions and give you all an update. Thank you!
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 09:54 PM   #14
Lukes31a
Junior Member
 
Join Date: Feb 2021
Posts: 6
Default Re: Can't get engine to idle down

UPDATE: I cannot even express the disappointment in my friend I had helping me with the car... I was going to make an excuse so I didn't sound like and absolutely goon but long story shot he was holding the throttle wide open thinking he was holding it closed. So I thank you all for the advise and will definitely be back on if I run into another REAL problem. Thank you all ��
Lukes31a is offline   Reply With Quote
Old 02-17-2021, 10:14 PM   #15
700rpm
Senior Member
 
700rpm's Avatar
 
Join Date: May 2010
Location: Portland, Oregon
Posts: 5,892
Default Re: Can't get engine to idle down

Where are you located? We can help you find a local club or even local experienced Model A guys. But we need your location. Put it in your avatar. It’s very helpful to have local experienced Model A friends. These cars are 90+ years old. They’re not complex, but maintenance requires specialized and experienced knowledge.
__________________
Ray Horton, Portland, OR


As you go through life, keep your eye on the donut, not the hole.
700rpm is offline   Reply With Quote
Old 02-17-2021, 10:49 PM   #16
redmodelt
Senior Member
 
redmodelt's Avatar
 
Join Date: May 2010
Location: Portland OR
Posts: 6,339
Default Re: Can't get engine to idle down

Thanks for letting us know, we all have things happen.
__________________
I know the voices aren't real but damn they have some good ideas!
redmodelt is offline   Reply With Quote
Old 02-18-2021, 07:48 AM   #17
Big hammer
Senior Member
 
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,114
Default Re: Can't get engine to idle down

Quote:
Originally Posted by redmodelt View Post
thanks for letting us know, we all have things happen.
x-2
__________________
Don't force it with a little hammer tap, tap, tap
get a bigger hammer tap done
Big hammer is online now   Reply With Quote
Old 02-18-2021, 10:45 AM   #18
shew01
Senior Member
 
shew01's Avatar
 
Join Date: Sep 2016
Location: Roanoke, VA USA
Posts: 1,905
Default Re: Can't get engine to idle down

Quote:
Originally Posted by Lukes31a View Post
UPDATE: I cannot even express the disappointment in my friend I had helping me with the car... I was going to make an excuse so I didn't sound like and absolutely goon but long story shot he was holding the throttle wide open thinking he was holding it closed. So I thank you all for the advise and will definitely be back on if I run into another REAL problem. Thank you all ��

Oh, that’s funny. Sad, but funny.


Sent from my iPhone using Tapatalk
shew01 is offline   Reply With Quote
Old 02-19-2021, 07:35 AM   #19
brokenspoke
Senior Member
 
Join Date: May 2010
Location: Anderson, Texas
Posts: 274
Default Re: Can't get engine to idle down

Your friend must be a Chevy guy
brokenspoke is offline   Reply With Quote
Reply

Thread Tools
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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 10:48 AM.