?

[78F250SCCS]

Why is my truck not shutting off when I shut it off. It kinda chugs a little when I kill the engine. Almost like its trying to running in the opposite direction. Its a 351m. As well I have a high idle, I really don't want to mess with the carb, because I have no clue what to do and am afraid of making it worse.

 

[Evan's f250]

Timing is a bit slow I'd say, this causes a dieseling effect. cheapy gas can make it even worse when the timing is off some. Bump the timing up a bit by mowing the distribitur. This will make the idle speed even more, but its pretty easy to set if you have a tach or just ear tune it. Simply turn the idle speed screw to the left to your desired rpm.

Untill, you fix the problem, you can shut it off in gear and then throw it in park after the engine is off. This will help stop most of the dieseling. Its hard on the engine to be doing this, cuz its running backwards.

 

[73F100Shortbed]

Lower your idle and you should solve the problem if it is high

 

[LEB Ben]

I'll be another to say idle or timing. Before I messed with idle, I'd get a timing light on there and see where' you're at.

 

[m78]

Used to be if you get a little carbon build up on the spark plug , it would get hot enough to glow and ignite what gas is left in the cylinder, which then would pump more gas and keep it going.

 

[Mil1ion]

Read me

http://www.misterfixit.com/deton.htm

 

[78F250SCCS]

Thanks for the advise guys. I changed the plugs before I parked it last year, so I hope its not that. I'll get a friend of mine who has a lot more know how than me to help me with every thing. Is there two idle screws, one under each barrel?

 

[Evan's f250]

should just be one screw for idle speed, it should be the screw thats to the left(driver side) of the carb. atleast for edelbrock and holley.
The 2 screws you're seeing are probably mixture screw, the idle speed screw will be all by its self.

 

[Fellro]

The idle screw is in the throttle linkage, not under the fuel bowl. The carbon deposits don't have to be on the spark plug, they can be anywhere in the cylinder, like on the piston itself. Some have used a product called Sea Foam to clean the carbon out. You have the engine running and pour it into the brake booster line. Otherwise, you could carefully pour it through the top of the carb. Easiest way is yo just put it in the fuel tank with a full tank and let it work slowly over time.

 

[Mil1ion]

Transmission fluid in the Gasoline works as well

 

[78F250SCCS]

Easiest way is yo just put it in the fuel tank with a full tank and let it work slowly over time.

In my truck that would be about two days lol. I've gone through $60 in gas since tues and have to fill up again. It cost about $60 to fill the front tank.