Okay so heres the deal,
I bought this 1984 f140 300 l6 300 rwd about 6 months ago because I wanted to start doing my own work on my vehicles and whatnot and I fell in love with it. It has 115 000 km on it. So far, the minor maintenance has been going real well and I am catching on quick. However I have a big challenge I am looking to take on.

My mileage has decreased significantly, having some issues starting the truck some mornings, blowing black smoke upon starting when there is issues and takes a really long time to get warmed up in the morning to where it isnt shaking out of its own paint. It has been +6 or warmer all winter so this worries me for once it cools down to our maritime winter temps. Aside from that she works unreal

I have done the plugs wires distributer cap rotor air filter changed oil and oil filter but it has not changed much. When it doesent want to start I have to hold the choke open with a clothespin to fire it up. Whern I do this it fires right up no issues though.

I am going to replace the o2 sensors nextand I was thinking of rebuilding my carb but I read something about DS2 dizzy and ignition systems? Can somebody who has done this or knows something about it please explain this in dummed down terms a little bit? I have read a real great post here in the forums on how to do it and whatnot but I need somebody to give me a little better understanding of what it is exactly and if it will help my problem.

I am 20, absolutely in love with my truck and learning how to work on it and absolutely any help or advice whatsoever would be greatly appreciated.

 

I think you just need a choke adjustment.
Is your choke, hot air with electric assist?

The DSII retrofit eliminates the feedback carburetor and the engine management computer.
It uses a vacuum controlled distributor and the round coil + DuraSpark module for ignition.

Seems like you have already replaced most of the ignition components.
Shame to throw all that away for lack of a simple adjustment.

ETA; Welcome to the forum!
Tell us where you are.
Nova Scotia, New Brunswick, Labrador, Newfie???

 

Do you know how the choke works and what it's for? You have obviously found the problem by using the clothespin.

 

well I am a born newfie who has lived in nb and ns most my life. Currently in Elmsdale nova scotia! How do i adjust the choke? I am really new to this, tell me about the choke. Thanks alot for the reply fellas.

 

And I think it is hot air.

 

Here's an instructional thread started by David, one of our more helpful members.

https://www.ford-trucks.com/forums/1...ent-101-a.html

I do not know if Canadian trucks were set up with "tamperproof" adjustments, like here in the U.S.
If your choke housing still has three conical stubs instead of screws that you can actually loosen, you may have to file a flat or cut a slot for a screwdriver to take them out and replace with conventional screws of the same pitch and diameter.

There is a detailed post in this thread too:

https://www.ford-trucks.com/forums/1...yfa-1-bbl.html

 

Aha, you know about the hot air system also? Is that intact? Does the line going into the choke housing in fact get hot when you run the engine? I would hate for you to adjust the choke when the hot air system is not working. That would be a effort in futility. Hot air going into the round choke housing makes it open. Then you would not have to use the clothespin to open it.

 

Some of the hot air chokes also had an electric coil in for aux heating. If so hours will have terminals - one for ground and the other probably for the stator wire off of the alternator. I ran Dad's on the electric choke for quite some time after the hot air system crumbled.

 

Excuse my ignorance but I am not 100 percent sure if it is hot air, how do I check?

 

thanks fr the instructional as well jim!

 

I think all Ford YF(A) carburetors are hot air, but only some use the electric assist.

You will see a metal tube usually surrounded with a braided fiberglass"sock" going to the choke housing.
There should also be a reddish rubber hose drawing vacuum.

You need to figure out why the choke is not closing correctly in cold weather.
David is much better at these I-6's, but the operation of the choke is the same with any carburetor.

There were some settings for closed and pulloff mentioned in one of those threads.
Find some time in the morning to check these figures while the engine is cold.

If you need to adjust the choke housing by turning it, make a mark across both halves first, so you can get back to where you started if you have to.
Try moving it one notch or line at a time.
Know that you will only have a little time to work on it before the choke warms up and you have to try again the next day.

You might ask questions of David in his thread.
He will probably have better answers for you than I do.

Good luck!

 

A hot-air choke has a pipe/tube into the round choke cover. This usually comes from the exhaust manifold and, by now, is frequently rotted off.

 

There is a bi-metal spring inside that round housing. When it gets hot it uncoils and it's hooked to the choke door by linkage behind the round housing.

Inside the housing there is a small "on purpose" vacuum leak. It puts a suction on the round housing. Hooked to the round choke housing is usually a pipe. This pipe runs down and goes near/through the exhaust manifold were it picks up heat. It then comes back up and hooks to another hose that goes to the carb where the system picks up fresh air.

So the vacuum inside the round housing sucks this warm air into the housing and that makes the choke open up.

 

I think there are some good pictures in that thread I keep pointing Connor to.

 

You guys are unbeleivable, if I ever run into a single one of ya ill be buying you a drink for sure.

So it is hot air and tomorrow I will be checkin er out.

Now would these minor adjustments really be the culprit to significant loss in fuel economy??