Sticky Carb
Thread Starter
|
Senior User
Joined: Mar 2001
Posts: 118
Likes: 0
Sticky Carb
Recently I have had to spray my carb to get the choke to operate smoothly. About once a week I have to pull the air cleaner off and unstick the choke from being open. It is making the engine run goofy and causing the truck to deisel when I turh it off. It is a 2bbl stock carb on a 79 F150 with a 351m. The carb has about 35,000 on it. Is it time to rebuild? Can I just replace the electric choke or are there bushings or something that may be bad? Thanks for any help.
Fleet Mechanic
Joined: Feb 2001
Posts: 1,290
Likes: 15
From: Toronto, Canada
Sticky Carb
I have the same engine/carb combo with the same problems. The stock choke unit should be operated by heat tubes coming from the intake, not by electric. I've heard that there is an electric choke conversion kit that is available for the motorcraft 2150, but my local parts store is not aware of it. I would like to upgrade to that if possible.
So check for clogged choke tubes and check your timing as well.
I've been told that high idle speed can cause the dieseling as well. According to my tach (which is accurate), my truck idles at 1000rpm (winter or summer). But it only diesels when the choke is on in the winter, but I guess that this could contribute to the dieseling condition.
So check for clogged choke tubes and check your timing as well.
I've been told that high idle speed can cause the dieseling as well. According to my tach (which is accurate), my truck idles at 1000rpm (winter or summer). But it only diesels when the choke is on in the winter, but I guess that this could contribute to the dieseling condition.
Fleet Mechanic
Joined: Feb 2001
Posts: 1,290
Likes: 15
From: Toronto, Canada
Sticky Carb
I am unsure if the vacuum diaphragm on my truck is working. It connects to the choke linkage, but the attaching rod slides thorough a hole in the arm of the diaphragm. Is this supposed to be stiffly attached?
What does this diaphragm do? DOes it help to disengage the choke?
http://members.rogers.com/mattjibb/vac.JPG
What does this diaphragm do? DOes it help to disengage the choke?
http://members.rogers.com/mattjibb/vac.JPG
Posting Guru
Joined: Aug 2000
Posts: 1,984
Likes: 2
Sticky Carb
Weldman, that unit pulls the choke open when the throttle is wide open. It is supposed to have a "sliding" type linkage. It comes into play when the engine is flooded, and you open the throttle all the way to start it.
79Slug, you can buy new choke spring and housing kits for the auto choke. The spring tends to wear out over time; this may cure your sticking problem. They are cheap, and it's worth a shot...
79Slug, you can buy new choke spring and housing kits for the auto choke. The spring tends to wear out over time; this may cure your sticking problem. They are cheap, and it's worth a shot...
More Turbo
Joined: May 2000
Posts: 655
Likes: 0
Sticky Carb
Maybe I just had too much time on my hands however....I removed all my choke linkage and polished it with emery cloth. I re-assembled it and it has never given me a problem since. I actually think my sticky linkage was due to corrosion buildup along the shafts where they pass through the carb. This is a spot the spray cleaner would never really touch.
Bob
Bob
Cargo Master
Joined: Sep 2001
Posts: 3,135
Likes: 0
From: Canada
Sticky Carb
what i did with my carb was sprayed it down good with carb cleaner. all nice and clean now 
Trending Topics
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Laughing Gas
Joined: Jul 2001
Posts: 850
Likes: 14
From: Fayetteville, NC
Sticky Carb
I got mad at mine last week and took the carb off and tore the choke down and cleaned it up. While I was putting it all back together I noticed that the curved arm that the high idle screw is supposed to ride on was bent to the side. I straightened this out and put a little dab of grease on it. Started the truck up and when it idled up I just backed the high idle screw up until it idled down. Now it doesn't idle as high anymore. Just something to take a look at.
1978 F-150 flareside. Primitive by todays standards but she was a jaw dropper back then. :-staun
1978 F-150 flareside. Primitive by todays standards but she was a jaw dropper back then. :-staun
