My truck was running rough and the exhast was spewing out a very gassy smelling mix. Based on previous experience,I replaced my carb over the week-end, but am struggling to get the choke to work while the truck is cold. Warm-up took a few minutes before I replaced the carb. Now the time has doubled. The carb does not choke down at all when cold. It is a stock Motorcraft 2 bl on top of a stock 360. I have completely tuned it up and I do not belive I have and vacuum leaks. The truck has more power now, but still seems to run rough especially when cold. I have not adjusted anything on the carb other than the choke housing that contains the themostat. Going left or right with it seemed to have no effect. The replacement carb has another element the old carb did not have. It is a vaccum operated thing that is connected to the choke linkage. It does have an adjustment screw on it. I disconnected the vaccum line to it to see what would happen. It had no effect.

How do I get the choke to work and get this thing to run better?

 

The choke thermostat or whatever, has vacuum coming to it from the carb where it bolts on. It it not a hose. I would just pull the choke off the other carb and put it on the one you have now. Is the choke electric, or run off a little tube that goes down into the intake?

 

The vacuum thingy is a "Pull off" which is suppose to open the choke fully.

I assume you still have the heat riser tube connected to bottom of choke housing?
When you were adjusting the choke housing, did you have the throttle held OPEN? You need to do this so that it allows the choke cam to operate freely without getting caught on throttle. If you didn't hold throttle open and tried turning housing, the cam was stuck and will not show any movement.

I used to adjust mine so that the choke was just barely full closed (when cold). I know there are notches on housing, but usually didn't follow them.

 

I also do it like Freighttrain. To many variables to go by the notches.

 

If the carburetor has a choke pull off = D2AZ-9S514-H (Motorcraft CK-1985), it will also have a choke control diaphram which mounts into the top of the carb: D0AZ-9J549-C (Motorcraft KM-1283).

 

Doggonit you're in Florida and you want a friggin choke? :/
I'm in AriDzona and here's my choke...

http://www.panix.com/~alvinj/file12/choke.jpg

That choke works good and -never- gives the type of trouble you're going-on about. ;)

Alvin in AZ

 

That's nothing, I'm in NW Washington State and my choke is wired open after the heater burnt up. It's been 2 years now and when I swapped carbs, I moved the old choke heater to the new carb and wired it open.

 

All the reason I like MANUAL chokes!!! Only gets it when I want it to, and for as long as I want.

 

But it ain't such a good idea when you are old and forgetful. I've been starting and driving no choke engines for better than 40 years and even my wife can get them to run.

 

Oh, I don't use the choke except IF I have to get out of truck and it wants to stall. I pull the choke plate OUT so all I have is high idle(that's all you really need). A couple pumps on the throttle will always get mine running with no choke.

 

Yes, even though it is hot here in FL, she still needs a choke. After numerous adjustments, I got the choke to work when the engine is cold. When it heats up, it idles too fast in neutral or park. It idles like a POS at idle in gear, hot or cold. At speed, it runs good. It still gets 6.5 mpg and the exhaust stinks so bad of gas, I can hardly stand to roll the windows down. There has got to be something else wrong, like maybe valves. Time to visit a mechanic since I am out of ideas! I am assuming the reman carb I got from Rockauto is ok. Changing to it from the old carb made little difference.

 

Try adjusting the jets and lean it out.

 

Yeah but both carburetors were acting the same, right?
Wrong? :)

As far as messing with a carburetor, they are easy once you understand them but it takes time and effort to understand them. Reading everything out there is at most half the picture. Especially when you read conflicting statements of "fact". :/

Too bad there wasn't a book written by real honest to goodness carburetor engineers! :/ So we could at least get the theory straight. ;)

Nu, you're in friggin Florida for crying out loud! :) ...wire the stupid choke plate open and start from there on getting the carb to working right. No kidding.

How many turns -from seated- are your mixture screws? :)
One to two turns? :)

Getting a choke adjusted when the weather is warm is tricky (at best) because of the small temperature difference between "cold" and warmed-up.

Talked about here, but not spelled out, is how bad chokes are for your engine.
Only worth-while (at a cost) when you really have to have it.

Bear 45/70's got me beat on the time frame... ~38 years for me. :)

Been modifying carburetors since 75 when i got my first VW dune buggy tho. :)

Got a 2 barrel Ford carburetor off an old 50's pickup ($1) and got it to work on a 40-horse VW engine with no hesitation that year. I was given a two barrel intake manifold by a friend and told...
"good luck, you're gonna need it;)"

A close friend of my father-in-law's started to tell me how to make that big of a carb to work on the fresh rebuilt 40 hp (1200cc) VW engine but then stopped and said...

"Noooo... change my mind, not going to explain it to you, just going to tell you -it can be done-, and you -can- figure it out... just the same as I did" -Doug Moeller, auto parts store owner and stock car driver

Nu, I don't want to play games with you... but if you say "I can't fix it"
...then I'll have to agree with you on that! ;)

What do you want to do? :)

So what do -you guys- say? :)
Two carbs acting the same way?
Fuel pressure to high?
Or what?

Alvin in AZ

 

Ok, got to agree on leave the choke WIDE OPEN/OFF until you get the thing running smooth otherwise. Don't need added issues while you get it tuned in.

How's the timing? Somewhere 8-10 degrees at idle? Ok.
First thing....how many turns out are the idle mixture screws? 1-2 turns? Should be for now.
After getting the choke opened completely, try starting the truck. A couple taps of the throttle should make it fire without too much effort. Once it starts, get it warmed up enough to get it to idle(set idle speed around 750 in neutral) and then start turning idle mixtures screws IN 1/4 turn each til it starts to slow down/stumble. Crank back out 1/4 from there to get it steadied. Reset idle speed if needed. Put in gear and see how far it drops off, and turn it up til it will idle and not die.

If things are still not running properly, then I would suggest start looking for vacuum leaks.

 

Problem solved. I was able to borrow a vacuum gauge and found 0 vacuum at the dist advance line. PO had blocked off the EGR at the manifold using alot of high temp silicone in the EGR port on the manifold. Overtime, the pressure eroded away the carb manifold gasket and the manifold base itself by the stud. I had not replaced that gasket, only the carb to space gasket, so I did not catch that. The best thing to do would be to replace the manifold,get a carb spacer and throw away the EGR that has not worked in 20 years. Instead I redid what the PO did, only better. Then re-did timing and carb adjustments. It runs great now. An extra added bounus was an easier brake pedal due to going for 0 to 20" of vacuum. I am now looking for a cheap aluminum manifold.