My motorcraft 4300 carb works fine on my 1971 T-B 429 in warm weather.
When cold weather set in, it still works fine after a complete warm up.
Trying to move the car before a ten minute warm up results in the engine
stalling and sputtering. By pumping the gas vigorously, the car will
accelerate after sputtering a bit. Each time I barely touch the
accelerator this happens. After warmed up, the car accelerates the way a
429 should. I know the accelerator pump is OK and is set properly. The
warm air valve on the air cleaner doesn't work at this time and I am
having trouble finding a new one.
face=Arial color=#000000 size=2>...<BR>> > My motorcraft 4300 carb works
fine on my 1971 T-B 429 in warm weather.<BR>> > When cold weather set in,
it still works fine after a complete warm up.<BR>> > Trying to move the
car before a ten minute warm up results in the engine<BR>> > stalling and
sputtering. By pumping the gas vigorously, the car will<BR>> >
accelerate after sputtering a bit. Each time I barely touch the<BR>>
> accelerator this happens. After warmed up, the car accelerates the
way a<BR>> > 429 should. I know the accelerator pump is OK and is
set properly. The<BR>> > warm air valve on the air cleaner doesn't
work at this time and I am<BR>> > having trouble finding a new
<DIV><FONT face=Arial color=#000000 size=2></FONT> </DIV><DIV><FONT face=Arial color=#800080 size=2>I would say the problem is related to
your choke, if you have one. You need a richer fuel miture when cold weather
starting, hence your pumping the gas pedal vigourously.</FONT><BR><FONT
face=Arial color=#000000 size=2>> ><BR>> <BR>>
Ahh yes, the old "wiggle the gas pedal on your Ford when it's cold trick" :) I
remember that one well.
Is there a tube with an insulated sleeve going from the choke housing to the
exhaust manifold? Ford used this for many years and I'm not sure when they
The choke housing was under a slight vacuum which drew heat from the manifold to
the choke spring. It was common for the tube to rust off of the manifold.
They later went to an electrically heated choke spring, the spring housing had
electrical connector on it. It's common to lose the ground connection between
choke cap and the housing. Either failure will cause the choke to stay on too
not open at all except via the choke pulloff.
It was a common "fix" to back the choke spring off until it only closed part
when cold (or block it completely open). Engine heat would eventually warm the
and open the choke. This "fix" would cause most of the problems you describe.
to wiggle the gas pedal on acceleration causing the accelerator pump to supply
fuel to overcome the lean condition.
Bottom line is to check all parts of the choke system and make sure they are
I used to have a 71 T-Bird, nice ride. I could squeeze 16mpg out of it on a
i kept it at 55 mph. Kinda hard to do with a 429 under your right foot. At 70,
would plummet to about 10 mpg.
Or just install a manual choke cable and YOU control it, rather than
some spring that never works right. I put a cable on every car I own.
My ford truck, my chevy car, and every car I have owned in the past 20
or more years. Automatic chokes are things that you are constantly
fixing and they still never work right. Not to mention the cost of
those choke coils. The one for my chevy car would have cost about
$60. The cable adaptor kit cost $12, and works better.
I like being in control, and that way I can tweak according to the
weather conditions. In the summer I rarely even touch it, when its
real cold I completely shut it.
I have a farm tractor and that came with a choke cable. The way ALL
engines should be.
All these things that are supposed to make life easier, only make life
And dont forget the bane of allus who used to wonder WTF when the first
really cold temps hit and car got cold-blooded
The exhaust "Heat riser"..
That's the dealy with the counterweight and spring between the exhaust
manifold and pipe, one side.
When cold is supposed to route exh through the intake to assist in
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
Need to know what the tube sticking out of the back of a motorcraft 4300
carburetor (ford 4-barrel)is for and is it supposed to be connected to
something? right above it is the hot idle compensator! I remember that
many years ago, the original Motorcraft 4300 had a rubber line hooked to
the back of the carburetor but can't remember where it came from. Does
the 71 Ford 429 have a spring loaded hot air valve in the exhast manifold
to divert heat to the intake manifold.
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