Running very rough. HELP PLEASE!
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Junior User
Joined: Sep 2008
Posts: 55
Likes: 0
Running very rough. HELP PLEASE!
just got home to the old girl and she is not doing well. Its a 76 f250 with a 4 barrel carb. when i started it i turned it over and brought it straight to fast idle, let it set there for a few minutes, then when i let off the throttle it almost dies. It is like swelling on 2 second intervals where its almost dead then alive and it just repeats this until i can't stand listening to it anymore and shut it down. HELP PLEASE!
Laughing Gas
Joined: Mar 2007
Posts: 754
Likes: 2
From: southwest Wisconsin
The first thing I would check is to find out if you have a stuck float or needle valve causing your engine to flood out. Take the air cleaner off and immediately after shutting off the engine look down into the carb to see if fuel is still dripping down into the engine.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
What "valves" are you referring to and what methods did you use to check? FYI, fastfarmer was referring to the needle valve in the carburetor which can very easily cause your problem.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 784
From: Simi Valley, CA
Some of these carbs use an electric dashpot, some do not, but the diagnosis is the same.
If the coil spring inside the dashpot has snapped, the accelerator linkage will not come to rest where it's supposed to, which kills the engine.
EZ way to find out if it's working or not. Use your finger to push the plunger in..then release the pressure. If the plunger springs back, it's OK...if not...it's time for a new dashpot.
If the coil spring inside the dashpot has snapped, the accelerator linkage will not come to rest where it's supposed to, which kills the engine.
EZ way to find out if it's working or not. Use your finger to push the plunger in..then release the pressure. If the plunger springs back, it's OK...if not...it's time for a new dashpot.
New User
Joined: Dec 2008
Posts: 23
Likes: 0
From: Sherwood
What a coincidence. I just fixed this problem on my truck today. Try checking your PCV valve. my truck would not idle when it was warmed up and when I gave it some gas All I could see behind me was Blue smoke, which by the way is another sign the PCV valve is out, but now that I have replaced it runs a lot better and doesn't burn oil after that. But there is a way to check the PCV valve also pull it off and shake it if it makes noise it's good if it doesn't it needs to be replaced or you can run the motor and see if it has any suction. But as 76f250highboys said check your vacuum lines too.
