351 double barrel problem
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New User
Joined: Jul 2001
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351 double barrel problem
Hey guys, I just had a new 351W put in my 85 3/4 ton, and new carb. Carb however has been giving me many problems recently. The truck in the morning will start, and will idle extremely low, and then die off. You can immedietly start the truck up after this, and I can feel the engine going to die, so when I put my foot on the gas to give the carb gas, it does absolutely nothing and just dies. After this, the truck won't start. I leave it for ten, fifteen minutes, come back to it, and it will start after winding for a while. Then, since the truck idles low when the engine is cold, it screams once it warms up, and I can't get it to idle down. Turning off the truck is a problem too, cause it will diesel, or post ignition fire, whatever you like to call it. It will diesel even when idling at low rpms. I've adjusted the carb three times already, and no matter what the carb still gives me trouble. It also no longer has that punch it used to have. It stalls while Im driving too, and seems to be going through fuel like its goin out of style. Im almost positive my choke is no good, but, what do u guys think? Thanks in advance.
Postmaster
Joined: Nov 2001
Posts: 3,351
Likes: 1
From: Escondido, CA
351 double barrel problem
Sounds more like you have a stuck float. If it's stuck it will cause the engine to die in the fashion like yours is. Look down the carb after it dies. Chances are you you will find that the throttle plates a really wet. Pull the fuel bowl and check for debris/garbage in you float shut off valve/fuel bowl. I am not sure what kind of carb you have but this is one way to solve the problem.
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New User
Joined: Jul 2001
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351 double barrel problem
maybe my choke and my float are bad? I don't even know anymore. The original Carb on the truck was manual choke so I could always get it to idle down and up as I wanted, the new one is automatic, so maybe the float is bad, causing the bad start, and the choke is bad, causing it to idle and diesel every damn day! Looks like I got a long day ahead of me tomorow!! 
THanks guys, anymore info would be appreciated greatly!
THanks guys, anymore info would be appreciated greatly!
Moderator
Joined: Jan 2001
Posts: 56,997
Likes: 2,746
From: Virginia
351 double barrel problem
Well, to experiment, scratch a mark on the choke housing from the black plastic part to the metal part of the carb to mark where you started. Then loosen the screws on the black housing and turn the housing radically toward the "leaner" direction as marked on the side of the housing. This will pretty much de-activate the choke. This will mean you will have to play with the throttle and pump the pedal to get it started, but after it's warmed up, you can see what it acts like. Once you get the feel of what the choke adjustment does, turn it richer till it acts the way you want it too. It usually takes me several cold morning starts before I get it right.
By the way, do you have a steel line running from the choke area on the carb down to the exhaust manifold? Or is it rusted off? This pulls warm air into the choke to help it pull off. Plus you should have a wire running from the alternator to the black choke housing.
By the way, do you have a steel line running from the choke area on the carb down to the exhaust manifold? Or is it rusted off? This pulls warm air into the choke to help it pull off. Plus you should have a wire running from the alternator to the black choke housing.
