Carburetor Choke Linkage Issue
#1
10-09-2011, 04:20 PM
Carburetor Choke Linkage Issue
Model specs in signature.
I think I have an issue with my choke valve, causing rich idle, or improper idle at the least.
I noticed something that didn't look quite right to me and it has to do with the choke linkage, and a vacuum linkage right next to the choke linkage (which in turn looks like it correlates with one another). I believe they are supposed to be connected, but I can't see how they would be. My shop manual doesn't go in depth or have any definitive pictures to display the linkage assembly so I had to come here.
I made a video, and tried to be accurate as possible. I'm surprised the video quality was that good too btw, I hope someone knows where my error lies, or if there is any error at all. Thanks In advance as always.
Here is the link to the video:
heathlive's Channel - YouTube
I think I have an issue with my choke valve, causing rich idle, or improper idle at the least.
I noticed something that didn't look quite right to me and it has to do with the choke linkage, and a vacuum linkage right next to the choke linkage (which in turn looks like it correlates with one another). I believe they are supposed to be connected, but I can't see how they would be. My shop manual doesn't go in depth or have any definitive pictures to display the linkage assembly so I had to come here.
I made a video, and tried to be accurate as possible. I'm surprised the video quality was that good too btw, I hope someone knows where my error lies, or if there is any error at all. Thanks In advance as always.
Here is the link to the video:
heathlive's Channel - YouTube
#2
10-09-2011, 05:12 PM
Poorman will probably jump on this like a chicken on junebug, but here's my two cents.
The linkage is correct. As vacuum is applied (probably by an opening thermovalve), the vacuum link will lift and open the choke fully.
If the vacuum linkage does not come on as the car warms, then either vacuum is missing or thermovalve is not opening.
good luck
The linkage is correct. As vacuum is applied (probably by an opening thermovalve), the vacuum link will lift and open the choke fully.
If the vacuum linkage does not come on as the car warms, then either vacuum is missing or thermovalve is not opening.
good luck
#3
10-09-2011, 07:10 PM
But the concern is also that the choke valve looks to stay open partially, about half way at all times...I thought possibly a sticky valve, but I sprayed carb cleaner and made sure it was able to move freely and it still stays open.
But looking forward to Poorman's reply too.
But looking forward to Poorman's reply too.
#4
10-10-2011, 06:52 PM
Chicken on a Junebug....dang from a boy that spent summers in AR on a chicken farm/egg farm that one killed me.....
Anyway-OP, I did own a 2nd gen MANY MANY moons ago when I was like 18. so it is a faint memory....know I really started learning on the 3rd gens (86-89) when I was 20 and that was 20+ years ago but still have a few. So I'm going to use what I know from those, sorry....didn't the hood open back to front???? Anyway
First, the butteryfly should be open (almost vertical-seeing the edge) when warm (~49 seconds in you state it should be like this when warmed up-NO). Like that, almost closed when cold. Not sure what the amb temp was when the video was take but without touching anything the "butterfly" looked about right-cracked slightly open
TX is correct, the "other" valve is (on 3rd gens) the fast idle unloader. Which works with the electrical choke stat. As a themo valve opens the vac helps "unload" the choke-opening it all the way. Now on the 3rd gens, they had an issue where the unloader would not work and cause the idle to hang at ~2500 rpm's until you "tapped" the pedal.
So can we back up a bit, what is the idle issue you are having? Meanwhile I think I have a shop manual around somewhere, I'll see if I can dig it out and dust it off.
Anyway-OP, I did own a 2nd gen MANY MANY moons ago when I was like 18. so it is a faint memory....know I really started learning on the 3rd gens (86-89) when I was 20 and that was 20+ years ago but still have a few. So I'm going to use what I know from those, sorry....didn't the hood open back to front???? Anyway
First, the butteryfly should be open (almost vertical-seeing the edge) when warm (~49 seconds in you state it should be like this when warmed up-NO). Like that, almost closed when cold. Not sure what the amb temp was when the video was take but without touching anything the "butterfly" looked about right-cracked slightly open
TX is correct, the "other" valve is (on 3rd gens) the fast idle unloader. Which works with the electrical choke stat. As a themo valve opens the vac helps "unload" the choke-opening it all the way. Now on the 3rd gens, they had an issue where the unloader would not work and cause the idle to hang at ~2500 rpm's until you "tapped" the pedal.
So can we back up a bit, what is the idle issue you are having? Meanwhile I think I have a shop manual around somewhere, I'll see if I can dig it out and dust it off.
#5
10-19-2011, 03:08 PM
Idling issues I have had are a lingering rpm speed, it just doesn't seem like a "clean descend" from lets just grab a number, 2000 rpms, back to ~800-1000 rpm. My idle with no power drawn such as headlights on, will be at 1k rpms, but with headlights and wipers going, it will linger about 700rpm +-50rpms.
So other than that, my idling seems to be okay.
But I still would like to address the weird choke linkage. If you look in the video more closely, you will see when I press the vacuum linkage (pull it back and forth) it doesn't grab the choke linkage until late in the vacuum pull. So that's what led me towards an assumption of faulty linkage, or a missing bolt.
A question I have that will help me better understand how this choke works- is the choke valve supposed to fully closed or fully open when AT engine temp?
-I just got internet in my new home, so It took me awhile to get back to this post.
So other than that, my idling seems to be okay.
But I still would like to address the weird choke linkage. If you look in the video more closely, you will see when I press the vacuum linkage (pull it back and forth) it doesn't grab the choke linkage until late in the vacuum pull. So that's what led me towards an assumption of faulty linkage, or a missing bolt.
A question I have that will help me better understand how this choke works- is the choke valve supposed to fully closed or fully open when AT engine temp?
-I just got internet in my new home, so It took me awhile to get back to this post.
#6
10-21-2011, 06:04 PM
Open when warm.
Closed when cold.
The linkage is a two part deal...kind of hard to describe. The unloader is one part. I think that is where your issue with a "hanging high idle from a cold start". This is based upon what I have found on 3rd gens (86-89).
The second part of the choke linkage is by the choke thermostat, electrically controlled.
I'll see if I can dig up a good pic of this two part linkage for a 3rd gen.....I've looked and can't find my manual for the 2nd gen....no idea what I did with it.
Closed when cold.
The linkage is a two part deal...kind of hard to describe. The unloader is one part. I think that is where your issue with a "hanging high idle from a cold start". This is based upon what I have found on 3rd gens (86-89).
The second part of the choke linkage is by the choke thermostat, electrically controlled.
I'll see if I can dig up a good pic of this two part linkage for a 3rd gen.....I've looked and can't find my manual for the 2nd gen....no idea what I did with it.
Thread
Thread Starter
Forum
Replies
Last Post
