Carburetor rebuild still didn’t fix the problem!!!

[Daniel Romero]

So my car (73 Fury III with 2B 400) has been bogging down when on the interstate doing about 80. It seems like it does it during hotter weather. If I am taking off from a stop up a hill and I press down too far on the pedal it bogs down and I have to lay off and feather the pedal for a while otherwise it still “stutters.” I have to keep the air cleaner lid flipped upside down to let more air in because if I don’t it will die out eventually and it won’t start until I flip the lid back over again. If I’m idling for too long (say like waiting in the drive thru when it’s especially busy) it will die out.
It did this before I had my carburetor rebuilt and it’s still doing this. It’s the factory carburetor. Do I need a better carburetor? Is it getting too much fuel and if so, why after I just had it rebuilt? Is it engine-related? Is it a gremlin? Have I been hexed by an ex? Please offer any advice.

 

[CBODY67]

Not the carb, but fuel supply TO the carb, I suspect. If the filter is recent, then it could well be the fuel pump push rod. Consider the fuel pump push rod "a wear item" on this or any other engine which might use one. They are not expensive, might just need to hold your mouth just right to get it at the right place for the fuel pump arm to hold it in place as you tighten the pump to the engine.

When the Holley 2210/2245 carb is working right, it works fine, from my experiences with TWO of them. Only other bolt-on OEM choice would be a Carter BBD 1.5" 2bbl from prior model years (actually a 1.56" throttle bore, just like the Holley 2210-family carbs are).

Just my experiences,
CBODY67

 

[Davea Lux]

So my car (73 Fury III with 2B 400) has been bogging down when on the interstate doing about 80. It seems like it does it during hotter weather. If I am taking off from a stop up a hill and I press down too far on the pedal it bogs down and I have to lay off and feather the pedal for a while otherwise it still “stutters.” I have to keep the air cleaner lid flipped upside down to let more air in because if I don’t it will die out eventually and it won’t start until I flip the lid back over again. If I’m idling for too long (say like waiting in the drive thru when it’s especially busy) it will die out.
It did this before I had my carburetor rebuilt and it’s still doing this. It’s the factory carburetor. Do I need a better carburetor? Is it getting too much fuel and if so, why after I just had it rebuilt? Is it engine-related? Is it a gremlin? Have I been hexed by an ex? Please offer any advice.

Run the engine at idle until it starts to die. Remove the top cover of the air cleaner and see if fuel is dripping down on the throttle bores with the engine off. If it is leaking fuel, the float is defective or set too high or there is a piece of crud under the needle valve. The other common problem if the carb is ok is that the EGR valves on these cars were famous for carboning up and sticking open. This will also cause the erratic symptoms you describe.

The engine bogging down at speed is usually an indication of a fuel delivery problem as noted above.

Dave

 

[PurpleBeeper]

You may have 2 problems. "In general", a "bog" is caused by too much air and/or too little fuel.
float too low?
vapor lock? (e.g. fuel boiling in carburetor or fuel line) - only happens when engine is hot
accelerator pump not squirting enough?
vacuum leak? (normally more noticeable at idle)

 

[saforwardlook]

I went through Hell trying to figure out why my 1973 Dodge Monaco with the same 400-2 engine/carb setup would bog when I would go heavy throttle.

What I found is something I never saw before or again. My car had the original exhaust Y pipe on the car and what I finally found was that those models in 1973 only as far as I know were dual wall Y pipes and the inner wall of my Y pipe had collapsed, thereby restricting exhaust flow under heavy throttle conditions. They must have done that for added noise control but it failed miserably in use. I believe that was perhaps the most frustrating issue I have ever had to figure out!

Let us know what you find....................

p.s. I found the collapsed pipe at the end of the Y where it connects to the intermediate piece that goes to the muffler. It isn't such a pain to take things loose back there........

 

[Gerald Morris]

I went through Hell trying to figure out why my 1973 Dodge Monaco with the same 400-2 engine/carb setup would bog when I would go heavy throttle.
....
p.s. I found the collapsed pipe at the end of the Y where it connects to the intermediate piece that goes to the muffler. It isn't such a pain to take things loose back there........

Constipated Exhaust SAS* will ruin an engine's proper running! The old single pipe setup on Mathilda might have once been so afflicted, judging from how the Y ruptured on it, then got welded several times, to no avail from the look of it. I just beer-canned it until I could replace all the pipe.

Like worms, internal combustion machines MUST excrete/exhale to function!

*Sure As Sheeeyuht!

 

[1970FuryConv]

Hi Daniel

I suggest checking your cooling system. Chrysler temperature sensors, in my experience, read low with age. Your instrument panel gauges may not be telling you the full story. A cooling system that is not performing up to par can cause problems at time of peak cooling system demand.

· 80 mph bog. That’s a time of high demand on the cooling system. If your engine is getting too hot you may be getting a partial vapor lock.

· Engine cuts off after idling for a long time. This is also a time of high cooling system demand. The fan has to be able to pull enough air through the radiator to keep your engine cool. Also your thermostat needs to be fully open.

· Some suggestions

· Fan shroud: extremely important for keeping a car cool at idle. If you don’t have one I strongly suggest getting one.

· Fan clutch: also extremely important for keeping a car cool at idle. Fan clutch gives fan speed which gives cooling. If yours looks old or original, I suggest replacing it.

· Thermostat: needs to be opening all the way, whether it’s high-speed cooling in hot temperatures or idle speed cooling in hot temperatures. You might try putting in a 160°F thermostat.

The cooling system suggestions above may help with your bog at wide open throttle acceleration, but that sounds more like a lean fuel mixture to me. If there’s an adjustment in your accelerator pump, you could try to richen the pump shot.

Good luck and please let us know how it goes fixing your car.

 

[Gerald Morris]

I suggest checking your cooling system. ....

· Fan shroud: extremely important for keeping a car cool at idle. If you don’t have one I strongly suggest getting one.

· Fan clutch: also extremely important for keeping a car cool at idle. Fan clutch gives fan speed which gives cooling. If yours looks old or original, I suggest replacing it.

· Thermostat: needs to be opening all the way, whether it’s high-speed cooling in hot temperatures or idle speed cooling in hot temperatures. You might try putting in a 160°F thermostat.

The cooling system suggestions above may help with your bog at wide open throttle acceleration, but that sounds more like a lean fuel mixture to me. If there’s an adjustment in your accelerator pump, you could try to richen the pump shot. ...

Take it from someone who drives daily in urban traffic in one of the hottest States on the continent, COOLING IS CRUCIAL!

If you have a clutch fan, do check the clutch. Thermal clutches are the sort to get. If you have a straight fan, stick with that, for now.

DON'T degrade the temperature of your thermostat down to 160F unless you drive a very old, Forward Look sort of machine. DO GET A HIGH QUALITY THERMOSTAT!!! The Robert Shaw sorts are the sort to get for our cars. I now use a Mr. Gasket 180F Robert Shaw clone, called a "racing thermostat" but if you look in the FSM and compare the drawing of a thermostat depicted there to a Robert Shaw, you will see that these were once the MoPar Standard. Stick with that. Getting such a thermostat has done more for my cooling system on a per dollar basis than anything else BUT:

An electric PUSHER fan!

Get a good 16 inch, 3000CFM rated electric fan to place in front of your radiator as a PUSHER, controlled ideally by both a manual toggle switch and a thermostatic one. Dollar for dollar, A-Team fans from Performance Parts, in Phoenix, AZ cuts the best deal, but Flex-a-Lite or DeRale are more reputable. I use the A-Team fan, and have for 4 years now. With it, my coolant hasn't gone over 205F during the HOTTEST DAY OF THIS SUMMER IN TUCSON, AZ!

Later, if you want, you can set up a totally electric cooling system for your engine, and use an electric fan or 2 as pullers, but as a supplement to an old school mech fan, use it as a pusher.

You may consider a radiator upgrade too. But for NOW, spend $40 on a cheap electric pusher, and see if by running it in traffic you get better engine performance. I think you will, even with other, serious problems.

·

 

[Daniel Romero]

UPDATE 9/23/2021:

I got true dual exhaust for my Fury last week! Since that the bogging down issue has been resolved, not to mention it sounds amazing! Made some progress and I’m happy about that. Still haven’t resolved the air cleaner issue. I’m looking to replace my factory air cleaner with an “open air” aftermarket one instead but seems like options are fairly limited that fit a 4 1/8” carburetor. If anyone has any links to sites that have one or an adapter that size please send them my way.

 

[saforwardlook]

So you didn't examine the original Y pipe to see if the inner dual wall had collapsed or not???? It would be nice to confirm whether it did or not as in my case so it could have been a teachable moment....

 

[Daniel Romero]

So you didn't examine the original Y pipe to see if the inner dual wall had collapsed or not???? It would be nice to confirm whether it did or not as in my case so it could have been a teachable moment....

I know that the problem was there before and now I know it isn’t. I’m content with that.

 

[1970FuryConv]

Glad the problem is resolved

 

[CBODY67]

For the time being, you can use the air cleaner base and "a top" from any open element air cleaner which might match the diameter of the filter element. Not pretty, but it'll work for a while (or longer).

The "bad" part about having an open element air cleaner is that everybody can see just how dirty the element is. Or that you didn't spend the extra money for a K&N, if that matters. Persoanlly, "Been there, done that, went back to a paper element", for me. The OTHER thing is that you can now hear INDUCTION SOUNDS from under the hood, under throttle, which can get a bit "old" after a while, by observation.

Enjoy!
CBODY67