1955 Problem with either the carburetor, fuel line or fuel pump

D

DiIanni

Active Member
Last seen
Joined
Aug 30, 2022
Thunderbird Year
1955
If my car sits overnight, it will easily start the next day. When I drive it for a short while, turn it off and leave it for awhile, I have an awful time trying to start it again.
Battery is fully charged, but I notice that very little fuel is in the clear glass bulb aside of the Carburetor. Typically with help from a kind Samaritan, with jumper cables attached and my continuously turning the engine over together with starter fluid sprayed into the Carb., in about 2-3 minutes the engine will start.
Please know that I have already tried insulating the fuel line within the engine compartment. Thoughts??
 

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The "teapot" carbs are well known to evaporate the fuel out in as little as a few hours after shutting off. If my car sits more than 24 hours, it will take a lot of cranking to start. This is with a rebuilt carb and electric choke. The solution was to add a flow-through electric fuel pump. Hit the switch on for about 10 seconds and hit start. Works every time. This in not just a Thunderbird problem. I have several classic cars and every one has a primer pump. Today's fuel will boil at 90F.

Since your problem is on restart, do you pump before starting? hold the pedal down at all? Using just the mechanical pump, if I do not touch the gas, it normally starts up. If I do press on the gas during starting, it will start but be very rich for a few seconds. Check the choke and float level. You may be flooding a bit on restart.
 
One of the problems with the 1955 models was he higher compression engines used in them. This change in engine design put the 6 volt starter at the end of it's ability to crank the engine fast enough to start when the fuel pump also needed a few cranks to refill the carburetor. Another problem is the use of 12 volt battery cables, further increasing the resistance to the starter and causing it to spin at a slower speed. I am not sure where you live, but in many states you can still purchase alcohol free fuel. it is a little more expensive, but I think it is worth the cost for the small amount of driving we put these cars through.

Go over your car with a fine tooth comb and make sure you have your engine timing and ignition system in TOP shape. Make sure you have the spacer between the carburetor and the intake manifold. Ford used a spacer made out of several carburetor base gaskets stapled together. You can purchase a phenolic block to place between the carburetor and the manifold. You may want to look at a 6 volt electric pump to be installed near the tank and use it to prime the fuel system.

It is very important to make sure the entire ignition, charging, fuel and starting systems are within factory specifications.
 
Do you have a phenolic spacer between carb and intake manifold? Have you checked timing? Really sounds to me you may be boiling out the fuel. Without looking at car it's only a guess.
I hate to admit it, but I have no idea what a phenolic spacer and/or where it goes and why.

The "teapot" carbs are well known to evaporate the fuel out in as little as a few hours after shutting off. If my car sits more than 24 hours, it will take a lot of cranking to start. This is with a rebuilt carb and electric choke. The solution was to add a flow-through electric fuel pump. Hit the switch on for about 10 seconds and hit start. Works every time. This in not just a Thunderbird problem. I have several classic cars and every one has a primer pump. Today's fuel will boil at 90F.

Since your problem is on restart, do you pump before starting? hold the pedal down at all? Using just the mechanical pump, if I do not touch the gas, it normally starts up. If I do press on the gas during starting, it will start but be very rich for a few seconds. Check the choke and float level. You may be flooding a bit on restart.
Whenever I try for a re-start after the car was driven for a bit, the float level is only 1/2 way up in the glass bowl and seemingly regardless of what I do it remains 1/2 full. It's only after I turn the engine for about 2-3 minutes it will start.
 
The "teapot" carbs are well known to evaporate the fuel out in as little as a few hours after shutting off. If my car sits more than 24 hours, it will take a lot of cranking to start. This is with a rebuilt carb and electric choke. The solution was to add a flow-through electric fuel pump. Hit the switch on for about 10 seconds and hit start. Works every time. This in not just a Thunderbird problem. I have several classic cars and every one has a primer pump. Today's fuel will boil at 90F.

Since your problem is on restart, do you pump before starting? hold the pedal down at all? Using just the mechanical pump, if I do not touch the gas, it normally starts up. If I do press on the gas during starting, it will start but be very rich for a few seconds. Check the choke and float level. You may be flooding a bit on restart.
Just inherited a 55. Similar starting problem. Is primer pump the only reliable way to solve the starting issue or will the clean gas be sufficient? Any tips would be appreciated
 
My 55 Thunderbird is still 6 volt and only has the mechanical fuel pump. I overhauled the fuel pump and carburetor myself so I know it is done right. This is the starting procedure I use:

Cold Engine - Sitting Overnight - Sitting For A Few Days
  • Do not touch the accelerator; crank the engine over for 5 seconds. (This not only fills the fuel filter bowl with fuel, it also builds up oil pressure)
  • Slowly push the accelerator pedal to the floor and then slowly release the accelerator pedal. (This closes the choke assembly and primes the carburetor with fuel)
  • Do not touch the accelerator; crank the engine over for 5 seconds once again. If the engine starts, rev the engine once slightly.
  • If the engine did not start, depress the accelerator 3 times, but only ¼ pedal travel each time. (This primes the carburetor with additional fuel, but keep in mind, T-Bird engines flood easily)
  • Crank the engine over once again and when the engine starts, rev the engine once slightly.
Warm Engine - Sitting Less Than An Hour
  • Do not touch the accelerator; crank the engine over and when the engine starts rev the engine once slightly.
Warm Engine - Sitting More Than An Hour
  • Depress the accelerator pedal ¼ pedal travel and hold it in that position. Crank the engine over and when the engine starts rev the engine once slightly.
doug7740
1955 Thunderbird Blue
 
There is a one way valve that can be installed in the fuel line right after the fuel pump. I tried it and had mixed reviews as it seemed to restrict the fuel too much. This item can be found at https://www.larrystbird.com/
I just installed an electric fuel pump prior to the stock pump that I would kick on for a few seconds before I hit the starter. Note that I only have to use it after the cars has set for a day. I purchased the auxiliary electric pump from CASCO and unlike some, I installed the pump per the instructions from CASCO which puts the pump on the frame drivers side just about a foot from the stock pump and it works perfectly!
 
All good advice being given here- From my experience with the little TBirds they love to boil fuel out of the carb after being shut down once the engine is warmed up and this no fuel problem can be compounded by the factory fuel pump if it is weak... This is the reason so many owners will install a phenolic spacer between carb and manifold to give it some insulation from heat soak and also install a inline elec fuel pump... Good luck! Get it fixed before we are back to TBird cruising weather🙂
 
If my car sits overnight, it will easily start the next day. When I drive it for a short while, turn it off and leave it for awhile, I have an awful time trying to start it again.
Battery is fully charged, but I notice that very little fuel is in the clear glass bulb aside of the Carburetor. Typically with help from a kind Samaritan, with jumper cables attached and my continuously turning the engine over together with starter fluid sprayed into the Carb., in about 2-3 minutes the engine will start.
Please know that I have already tried insulating the fuel line within the engine compartment. Thoughts??
I'll sum up from all the good advice here on what works for mine. Mine is 1955, 6v. I installed in-line 6v electric fuel pump along frame rail under the driver's seat. Runs continuously into existing mechanical pump. Also very important today that hasn't been mentioned is a fuel pressure regulator valve...leaded gas weighs considerably more than unleaded. Our vintage fuel pumps push approx 7-8 lbs which will cause flooding & black smoke out the back with unleaded gas. Install valve in-line before the carburetor and set to 3 lbs. https://www.amazon.com/Holley-Press...5-9PSI/dp/B09BTBW5VP/?tag=thunderbirdforum-20
COLD - I turn my key on and let electric pump pressure up (you'll hear resistance in the pump motor). One full pump of gas pedal to the floor (squirts gas into carb and sets choke). Turn key to start, no further gas. My car starts instantly when cold. I live in Houston, very little choke needed here, only to first detent. Below 40F you might need more choke. HOT - I've typically pushed gas pedal to floor and crank. Takes a few cranks and black smoke out the back. Lately I've tried putting car in N before turning on key not to activate the electric pump, then turn on straight to start. It has started more quickly the few times I've tried it. BUT - the pressure reduction valve is very important. Comes with a guage: https://www.amazon.com/Holley-Press...5-9PSI/dp/B09BTBW5VP/?tag=thunderbirdforum-20
 
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