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Stalling problem on 1935 Buick Special

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Gentlemen, I have a 1935 Buick Special 46C.  It has a straight 8 engine with 222 cubic inches.  The car starts well and runs 

well.  A good driver.  The problem I am having is after driving at speed when coming to a stop the car will sometimes stall.

I recently adjusted the clutch to make sure the transmission was disengaging from the engine.  That seemed to help some.

When I purchased the car the idle was set high so I reduced the idle.  Is it possible that the idle was intentionally set high

to prevent the problem I am having?  Or is it something else.  A friend suggested the carburetor was set too rich and should 

be adjusted.  He said when following the car that he could smell gas after I had to restart the stalled car.  This could have

been a flooding issue.  

Any help will be appreciated.


John P.  #50690

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There are two idle mixture control screws (brass screws, with the calibration held by a spring). These control the amount of idle fuel.


These should be adjusted from 1/2 to 1 1/2 turn from lightly seated.


So, suggestion:


(A) with the engine cold, gently screw each idle mixture control screw clockwise UNTIL LIGHTLY SEATED, DO NOT OVERTIGHTEN.

(B) record the number of turns for each

(C) reset the screws as they were

(D) start the engine, and run at a fast idle UNTIL OPERATING TEMPERATURE IS REACHED, maybe 8~10 minutes

(E) Turn the throttle positioner about 1/2 turn clockwise which should significantly increase the idle RPM

(F) Reset both idle mixture control screws AS FOLLOWS:

(F-1) Fresh engine (less than 500 miles) 1 1/4 turns from lightly seated 

(F-2) Good engine with more than 500 miles 1 turn from lightly seated (you might later wish to try 3/4 turn)

(F-3) Engine with multiple thousand miles, low compression, burns oil, should be rebuilt 1 1/2 turns from lightly seated

(G) slowly turn the throttle positioner screw clockwise until the desired idle is reached.

(H) test drive - you may need to tweak the adjustment.


EDIT: typo - (G) should read counterclockwise. Jon.




Edited by carbking (see edit history)
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Here is your picture.  Josephine, which is her name, was a frame off restoration done well over 10 years ago.

She is a 46C Convertible with a rumble seat.  The trunk has custom fit luggage from 1935.  The engine is a 

straight eight of 230 cubic inch generating 92 hp.  The color is Raleigh Blue which is the original color.

Currently I have Josephine in a paint shop getting some touch up work done.

Thanks for your interest.

John P.  #50690



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On 11/23/2019 at 12:19 PM, 1939 Cadillac LaSalle Coup said:

Thanks for the response Bob.  Idle circuits?  I don't know what those are.  I simply adjusted the set screw to increase or decrease the idle speed.

Re clearing idle circuits:  This has worked for me a dozen times, although Jon may recoil in horror.  One at a time, remove idle mixture screw (after counting turns as Jon specified), then spray some aerosol carb cleaner into the idle mixture screw orifice, with a rag around the spray tube maximize the penetration, followed by a light blast of shop air.  Then reinstall the mixture screw and proceed to the other one.

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