BBD carb settings

ALLAN

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just had to clean the BBD carb on a 1970 318 Dodge auto, was ok till I floored it and blocked every orifice, ended up getting a small cup full of crud out, honest, never seen so much. anyway I now have to undo decades of 'tweeks to keep it running' but am unable to find base settings for idle jets. Hot or cold it takes lots of cranking and pedal to the floor to start, once started its sweet as a nut and drives fine. I set the needles at fully in then out 4 turns. On strip they were 1/2 a turn out and the car wouldn't start after cleaning. When cold the choke ( top butterfly)is fully closed should there be a gap?
 
Got to mymopar.com and download the service manual, you can get the carb rebuild and adjustment instructions for there.
 
Idle mixture screws usually had a "base setting" of 1.5 turns out. At 70 degrees F AMBIENT (air temp and also carb choke thermostat/engine temp), the choke valve should just close by itself. When the engine starts the choke pull-off will pull it open (against the thermostatic spring pressure) a specified amount (which is set by the bend in the linkage from the chokes pull-off to the choke linkage). Should start reasonably easily when all is well.

Check ALL of the passages in the venturi cluster to see if they are open. Just because they might flow carb cleaner does not mean they are open enough to work correctly (as I discovered once upon a time with a '80 BBD).

Where did all of the gunk come from? How long had the car been setting before all of this happened?

Other than the idle speed and mixture, that's all that really should need "setting". Other than possibly the fast idle speed and such.

Just curious,
CBODY67
 
As you can see it was quite a bit! We've not had the car long and it's never given any problems, took the top off the carb and stood back, the floats were resting on the crud. Lot smoother now just have to sort out the starting

IMG_20190506_165546.jpg
 
I am assuming with the automatic choke the start process is the same as ‘68. ( after initial adjustments per service manual)
Cold start- press accelerator pedal all the way down and let off. Your plunger squirts gas in and it resets the choke and fast idle cam.
Warm start- (engine warm) press pedal 1/2way down and hold. Puts a little fuel in leaves the choke open and opens your butterflies a bit.
Extra cold starts (around zero)- press all the way down to squirt fuel and reset choke and fast idle. Only release the pedal 1/2 way.
It is amazing how well these procedures work.
 
At least in the less-cold winters of N. TX, the "1/3" method works for all seasons. It only takes a little throttle movement, with a cold engine, for the automatic choke to activate the fast idle cam and for the choke plate to close.

KEY thing is to learn what works best for YOUR car, using the factory recommendations as a guide and progressing from there. IF it seems to need more pumping than the factory procedures, then something's not quite right, by observation.

Enjoy!
CBODY67
 
I am assuming with the automatic choke the start process is the same as ‘68. ( after initial adjustments per service manual)
Cold start- press accelerator pedal all the way down and let off. Your plunger squirts gas in and it resets the choke and fast idle cam.
Warm start- (engine warm) press pedal 1/2way down and hold. Puts a little fuel in leaves the choke open and opens your butterflies a bit.
Extra cold starts (around zero)- press all the way down to squirt fuel and reset choke and fast idle. Only release the pedal 1/2 way.
It is amazing how well these procedures work.
I'll try theses, it does start better if I press pedal fully down.
 
thanks for all your help, car is now starting much better and running beautifully , just needs a little fine tuning and some learning on my part.. I sold the residue to the local fracking outfit..
 
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