1955 engine issue accelerating | Ford Thunderbird club group 1955-2005 T-Bird models

1955 engine issue accelerating

  • Thread starter Thread starter NickIt
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NickIt

NickIt

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Thunderbird Year
1955
The engine is a 292 three speed auto with a teapot carb...everything goes perfect speeding up till 2nd gear but when the gear shifts in 3rd gear the engine starts to stall and the same happens going uphill...
Can anyone help me?
Nick

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NickIt said:
The engine is a 292 three speed auto with a teapot carb...everything goes perfect speeding up till 2nd gear but when the gear shifts in 3rd gear the engine starts to stall and the same happens going uphill...
Can anyone help me?
Nick
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Check your vacuum advance for ruptured diaphragm.
 
There are two vacuum passages that supply vacuum to the distributor vacuum advance. The primary passage is at the venture (that’s why you have to set the base ignition timing with the distributor vacuum line disconnected) and the other passage is at the throttle plate. At idle, when the throttle plate is closed, venture vacuum is higher and it raises the check ball in the vertical passage sealing off the than the passage to the throttle plate. This prevents venture vacuum from escaping through the throttle plate passage.

All of the vacuum to the distributor vacuum advance passes through the spark control valve. When accelerating and the vacuum at the throttle plate is high, the spark control valve closes the passage from the throttle plate to the distributor vacuum advance preventing too much advance or a controlled amount of advance. So, at idle next to nothing is being sent to the distributor advance diaphragm. The Holley manuals provide a chart with typical vacuum and advance figures under different throttle positions. The chart shows the advance starting to move at .16 inches, the decimal point is correct, .16 inches of vacuum at approximately 600 rpm. Full advance is reached at less than 3.0 inches of vacuum.

doug7740
1955 Thunderbird Blue

Vacuum Advance.JPG
 
As well as Doug7740 diagnosed your problem and did an excellent job I might add,I have a completely different thought. Put the carb and the distributor in a box to give to the next owner so the car stays original. Now you can purchase a real carb and intake and distributor Edelbrock or Holley do a great job.Edelbrock might even have a package for your carb and the car will run better than new.
 
NickIt said:
The car accelerates well in first and second gear but starts stalling in third....

Nick
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Can you elaborate on what you mean by "stalling"? Both the ignition system and fuel systems are most heavily stressed under high load and high rpm conditions. Third gear puts the highest load on it when at high rpm. So when you say stalling does the power drop off feel like it's sort of wobbling up and down as fuel levels come and go in the bowl, or does it feel like it has a sharper power/no power condition as the ignition system breaks down and sometimes the plugs fire and sometimes one or more of them don't fire?
 
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