I think my choke is messed up

[mudslut79]

When i go to start the truck i only have to pump the gas pedal once runs good rev it up to kick the choke off. It revs really fast and good when the truck is in nuteral as soon as i put it in gear and try to do a burn out it cant spin the tires just kinda chugs then shuts off. Its got a brand new fuel filter i had the carberator rebuilt new distributer cap rotor plugs and wires. I even had the mechanic tune the carburator and he redid the timeing at the same time still nothing. Plus when i get on the gas pedal alot it hesitates need suggestions to help fix my doggy modified i tried about everything.

 

[LEB Ben]

Well carbs usually require a warm up time, especially in colder temps. How long are you letting it warm up? I know my carbs are well tuned, and they usually take 3-5 minutes during the winter to warm up properly...or I drive 2 footed until it warms up. You should have a heat riser (think that's what it's called) that helps warm up the carb a little faster. During the summer, I don't see this to be an issue as much.

 

[mudslut79]

Thats the only time i drive it is during the summer. And i usually let the truck warm up for 5 or 6 minits before i jump in it.

 

[TexasNomad]

What kinda carb do you have?
I've found this problem is most likely a miss tuned carb meaning ideal mix and or floats and a miss adjusted squirter can kill a take off.

 

[mudslut79]

Its a factory 2 barel motorcrap carb.

 

[Mil1ion]

I suggest to change what you're doing into something more patient.

Don't be so demanding so early in the *running to achieve normal operating temperature*

Just call the carb tempermental.

 

[mudslut79]

I have done that before i drove the truck 30 miles up to greenbay was totally warmed up still did the same thing how tempermental can these carbs be?.

 

[TexasNomad]

OK you've checked for any vac leaks on all the lines and the mounting gaskets.
Check around the base of the carb and behind the carb for any holes, my old Mofo carb rusted out and a small hole opened up and gave me living hell until I took the carb off the engine and checked out it..

 

[dakonthemountain]

my understanding is that Motorcrafts, over time, do develop the problem of the "miss" when putting your foot into it. That was my problem on two different trucks. A rebuild did not help it either. Vacuum leaks did end up helping, but after rebuilding the 4bbl on my truck twice and still having this problem I gave up. I know this isn't much information to go by, but just my experience. good luck!
Dak

 

[LEB Ben]

my understanding is that Motorcrafts, over time, do develop the problem of the "miss" when putting your foot into it. That was my problem on two different trucks. A rebuild did not help it either. Vacuum leaks did end up helping, but after rebuilding the 4bbl on my truck twice and still having this problem I gave up. I know this isn't much information to go by, but just my experience. good luck!
Dak

That's interesting you say that Dak...my dad (who was told by his dad a Ford master mech) told me that same thing when I got the Bronco and was having the same problem with my stock carb...but I had never heard that before or again until now. Any clue what causes that 'miss' or is it just due to age?

 

[dakonthemountain]

I can only assume it is age, and not necessarily mileage. My first one had a total of 143k on it and was rebuilt once. Burt has 95k on him now and I took the Motorcraft out at 92k after being rebuilt twice. A Ford mystery!
Dak

 

[1970Custom]

the Motorcraft wasn't known for performance, it's was simple and meant for economy (relatively speaking) not all out performance, that's what the after market parts supply is for...

That and most carbs will have the stumble when it goes from idle to WOT, kinda like flooding it (actually it is like it, instantly dumping a whole bunch of fuel in at once)...

 

[Mil1ion]

Throttle rod bushings are prone to wear out and leak causing stumbling.

Take a unlit propane torch and point it at the bushings to hear if the engine smooths out and pick up speed.

 

[TexasNomad]

I'd really see about getting about carb man.
JEgs sells 2bbl for around 200 I think.

 

[1985 Ford F-150]

I got four of them things sittin around the house.

 

[77FordTruckMan]

I have this same problem with my Motorcraft 2bbl but it smooths out after driving it a while. Sometimes it even seems like it shut off, but then it kicks back in. It also takes a lot of tries to start it after it sits overnight, sometimes as many as 7 or 8 unless its warm or really cold, because then the choke works right. I am planning on upgrading to a 4bbl but I don't know when I'll get the money.

 

[Alvin in AZ]

My weather changes from dry to wet to hot to "cool" over night here.
http://www.panix.com/~alvinj/file12/choke1.jpg
"nothing wrong with a choke a hacksaw can't fix!"

Stumbling 2100...
Mine was from being too lean in the low speed circuits.
http://www.panix.com/~alvinj/file12/booster.jpg
That's the tips of the low speed circuits' down tubes peeking out from
the bottoms of the emulsion tubes. One that was pulled out from another
booster assembly is laying there too.

The restricting jet is pinched into the bottom, ream it out a little and try it.
Use a micrometer and jet reamers or progress from #70 to 1/32" to #66 to
#64 to #61 to #58 say up to 3/64" drill bit.

Check out those emulsion tubes... if your's only has holes up near the top
you've got the crummy kind! :/ Why they even put those in any production
carburetor is beyond me.

If your's has holes running up two sides, then you've already got the good
kind.

Swap out the whole booster assembly, the dangged stuff isn't made to have
parts swapped around. :/ Or solder up the holes at the top of your emulsion
tubes and drill holes down the sides.

Adjust the fuel level.
Figure out if you've got the right main jet size.

Only way to really know if you've got a vacuum leak is with a vacuum
pump/tester. BTDT and the WD-40/propane/carb cleaner trick didn't work
for me -at all--. YMMV?

1985 Ford F-150
I got four of them things sittin around the house.

Cool.
Are you into carburetor modifying/tinkering too?

Alvin in AZ

 

[1985 Ford F-150]

Ive just started figurin out how to tune em. I mostly have accumulated em from the different motors ive picked up that had 2 bbls. Since you were talkin about the holes in the booster and the holes goin all the way up on both sides I think im goin to see if any of my carbs have that.

 

[mudslut79]

All the emissions stuff has been took off the truck but i blocked off the vacume leaks with caps.