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She wants to stall when going down steep grades.

Kern Dog

Life is full of turns. Build your car to handle.
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The Charger starts and runs great BUT when I went out for a drive today, I went through some areas with fairly steep grades. On level ground and going up, the car acts normally. Going down hill, the engine wants to stall. I had to pop it into neutral and rap the throttle.
I'm guessing fuel level in the carb but they both looked fine the last time I checked.
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It is a Barry Grant Speed Demon 850 Vacuum Secondary carburetor. I have a regulator with a return line to the tank. I get no vapor lock with this setup.

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Maybe 15 to 20 degrees.
 
It shouldn't have a problem at that angle. I suspect that you are getting more fuel than air. Check out the floats. I had a 66 Bronco years ago and ran a Holley carb on it. I had similar issues but on more severe angles. I modified the carb with vent baffles and the vent hose trick. I would never run a Holley on a 4x4 again. I ended up swapping it out for a Carter and never had problems again. A Holley will get you down the quarter mile quicker but if you are not on flat ground they are notorious for flooding and stalling. It's the nature of the beast. I know you are running an electronic fuel pump. What fuel pressure are you running?
 
It is actually a Carter mechanical that was pushing around 10 psi. I use the regulator that allows approx 3 psi at idle with a 7 psi max.
 
Sorry to confuse you. I was referring to my Broncos carb but the basic operating principals are the same for float level. I would pull the bowls and check the float height and for any debris or obstructions. It sounds like its flooding and when you are pumping the accelerator you are giving it the air it needs to keep it from falling on its face. If you had an air fuel ratio gauge it would verify this. The power valve rarely blows on your carb model and your only problem is at angle so I would rule that out. I think your thoughts are headed in the right direction in this one.
 
My first thought was the float levels....but I have another thought that it might be the vent tubes in the tank - crossed over, and not allowing the breather function to work...creating a vacuum in the tank. This would become apparent on a long downhill or steep continuous climb.
I know a symptom of vent lines crossed over is the smell of gas in the garage, and vacuum condition in the tank....worthwhile checking it out. There could also be an obstruction in the vent tubes on the tank, but that should cause a problem on the flats as well.
 
The Charger starts and runs great BUT when I went out for a drive today, I went through some areas with fairly steep grades. On level ground and going up, the car acts normally. Going down hill, the engine wants to stall.


This manual was obviously written for you. They even have a caricature of you at the controls. :D

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That carb has no business being one a Mopar IMO. Sorry, I’m not a Holley fan.

It does sound like floats. When you restart it, what happens? Fires right up, hold it open, etc? If it’s flooded I would lower the floats a little and see what happens.

BTW - is this what your working on? Those are some pretty steep angles unless you’re in Pittsburgh.
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Kern Dog - set your rear float level to the bottom of the sight glass and re-check the operation. Also, are your motor mounts in good shape?

I have used several BG carburetors over the years with great success. To me, they are a better made “Holley” design.
Ron
 
Kern Dog - set your rear float level to the bottom of the sight glass and re-check the operation. Also, are your motor mounts in good shape?

I have used several BG carburetors over the years with great success. To me, they are a better made “Holley” design.
Ron
If they were better than holley,,,,,,,,,they might still be in biz.
 
One must place that squarely on the management and oversight. Holley must have thought there is a market or they wouldn’t still be manufacturing them?
I personally have had more issues with Holley carbs poor materials dating back to 1973 than with any BG. I still run one on my RR.
YMMV
Ron

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I wouldn't think any of us males would complain too much if "she stalls when going down...".
That's fine, sweetheart, take all the time you need down there. :)
 
KD, first try should be lowering rear float a tad, IMHO.
 
You ended up with my Demon! Get efi. Good on hills just pisses fuel from surging after shut off. We have choices.
 
Ha...
I have no intention to convert this car to fuel injection, man!
I do have an air/fuel gauge. I just didn't think to look at it when the car was stumbling. The carb was rebuilt last fall.
 
Kerndog, sounds like you need a good old fashioned carb teardown with new gasks etc and PV. You need to poke something like pin gauges etc. through all the ports and I even remove the throttle shafts and plates to clean and realign during reassy. There is some kind of crud/corosion that sticks in the ports and all surfaces. Put a small drop of lube on all threads and a new filter. Seems to me that all carbs need a good need a good going thru every couple of years. Barry Grant carbs were the big thing years back, I remember walking thru the pits and all the top runners had BG equipment and I still have 3 BG carbs and will continue. I have a BG carb book if you need any info. Quite a story about Holley and the BG delimma but looks like Holley just about owns it all now. Good luck
 
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