Hard Starting '54 Savoy

[plym_46]

Two things are most likely at fault.? the coil as discussed before, and Fuel perculation.? We can discuss Vapor lock later.

Fuel perculation can cause a flooded condition ( hint look for raw fuel leaking past the ends of the throttle pivot rod.

So when you start a hot engine you should follow the procedure in the owners handbook, which do not pump the gas pedal, hold it 1/2 to 3/4 open and then crank the engine.

Fuel perculation is addressed by slighly lowerint the fule leven in the float bowl by adjusting the float level so there is less fuel inthe bowl then what the factory spec calls for.? Here is the deal;

Fuel in the float bowl expands as it acts as a heat sink under the hood, this expands the fuel (especially with todays more volatile [you can look up the meaning of volitile] gas blends.? Thei expansion oveflows the bowl and washes down the carb.? Taht is where the leakage afound the throttle pivot comes from.? Thei lowers the float and allows more fuel from residual pressure into the bowl where it expands, overflows, lowers the float and overflows the carb, three or 4 cycles of this will empty the fuel in the line from the pump to the carb, leading to a flooded engine with an empty carb bowl and a gap in the fuel flow.? None of these conditions is vapor lock.

As hood lines lowered in the 50's the intake manifold design changed.? This change reduced the height of the carb mounting casting.

There is nearly a 4 inch difference in the hight of my 46 mainfold as opposed to my 56 manifold.? This difference put the carb on the newer cars lower and closer to the heat from the exhaust manifold, increasing the likelyhood of perculation.? You should have a sheet metal heat shield on you car between the manifold and carb.? Also you can add (factory ourists trun away) a phenolic insulator/spacer
between the heat shield and the carb.? These are availabe from Tom Langdon (they were standard equipment of Chevy 6's he has them in stock for less then 10 bucks.? If you add these items you will need a couple more gaskets and also make sure you keep the vacuum feed from the manifold to the holes in the base of the carburator.? These feed the intermediat power jet valve, and if you get no vacuum that jet will be opened all the time affecting a rich condition and lower gas milage.

So assure you heat shield is in place between the carb and intake, readjust you float a bit, add the manifold to carb spacer.? If your coil is good and you follow the hot start procedure, and you coil is good, I assure you your hot start problems will lessen or dissapear.

[David Pollock]

Since you have covered all the usual reasons for hard starting, I will give you another, which is not so well known but will make your car a s.o.b. to start when it is hot.  Does your car also use a lot of water?  If so you have a leaky head gasket which may not show up on a compression test as it is not leaking between cylinders, but it is allowing coolant to be drawn down the three head bolts which are  over the intake ports. This steam effectively shorts the ignition inside the cylinders.  Put a can of stopleak into the radiator as a temporary repair. If the hard starting is cured then the problem is as I outlined. Remove the head, have it surfaced and install a new gasket.

[Eddie M]

The term vapor lock has become a catch all for engines not starting. Can someone explain to me how fuel from the discharge of the fuel pump (that is under higher than atmospheric pressure) can change state from a liquid to a vapor? Remember the boiling point of any liquid increases as the pressure rises.

The same way water vaporizes at 212 degrees fahrenhiet.  Don, the fuel system at best is under 6 pounds of pressure when running, it falls as soon as you turn the car off.
If a fuel line is running next to a hot engine 210 F or an exhaust manifold/400 F that fuel will vaporize very quick.

Yo Elmo, did you look at my answer #1?  Vapor lock was one of the possibilities I wrote down.

[Don Coatney]

Two things may be happening here and neither one of them is the imaginary vapor lock. Have you replaced your ignition coil? Frequently a failing coil when hot will not fire or produce a weak spark. Next time this happens pour a bit of cold water over the coil or better yet cover it with a rag full of ice cubes to cool it down. Then try and start your car. The other possibility is your starter motor is drawing high amperage and not allowing your ignition to get sufficient voltage to fire the ignition system. A good old mom and pop electric motor shop can check this for you.

The term vapor lock has become a catch all for engines not starting. Can someone explain to me how fuel from the discharge of the fuel pump (that is under higher than atmospheric pressure) can change state from a liquid to a vapor? Remember the boiling point of any liquid increases as the pressure rises.

[elmo]

Go is right it sounds as if you have a vapor lock problem , I have a 54 DeSoto Diplomat which is a plymouth in disguise, apart from the grill ,badges and some trim it is purely Plymouth . i had a vapor lock problem untill i fited a heat sheild between the carb and manifold , i was lucky and found an original , i dont know what the laws are in the US , but they are made of asbestos so you could have a problem getting one . there is also a heat sheild that goes  between the manifold and petrol pump that is made of metal and is quite easy to fabricate . i have not yet had the need to fit a electric pump as we dont get the weather extremes here in New Zealand as you do in the states and somes parts of europe,but i am thinking of fitting one to the 39 DeSoto that i am restoring

[Go Fleiter]

Your car probably suffers typical vapor lock problems: Exhaust is hot, all gas in the surroundings is evaporating and forming gas foam at best. Your poor starter has to turn the whole enging for minutes until fresh (cold) gas has reaches the carb. The first flood of fresh gas will even evaporate too. Than, impatiently pressing the throttle, too much gas may moisten the plugs making starting even worse.

I was definitely bored by this I solved my Vapor Lock problems with a shunt electrical Gas Pump. It is fixed with tube wyes and hoses  plus clamps. See sketch.

It  just has to flood the hot carb without having to turn the whole engine with starter motor. It is 12 V and fills the carb within 10 seconds.  My e-gas pump setup is only used for the starting procedure, as the mechanical pump is in good working condition. I have a toggle switch. (normally open, closes only while pressing). If not, in an accident: the pump will continue to spill gas on the road. There are security electronic devices to avoid accident spilling, but I didn?t find one for 6 V.

If Your original pump fails while driving, You can use the e-pump as temporary replacement too to reach home. Swich has to be bridged or fixed in closed position.

Car starts every time now with hot or cold engine - .

Check: There should be a heat shield between carb and manifold.

The car will not be eligible when judged, unless You unclamp all back to the original setup.

Greetings ! Go

[Eddie M]

I would look at the carburetor for a couple of things.
If the accelerator pump within it is bad, it will allow fuel to pass it while the engine is off and flood out the engine.
That would account for hard starting hot and cold.
Make sure your carburetor choke is setting properly that too can account for a hard start when cold.
Make sure your fuel lines are clear and not rotted.  Make sure no fuel line is too close to the hot points on the engine.
This can cause vapor lock when attempting to start the car when it's hot.
Make sure your ignition dwell and timing are on their mark also. This is the same reason as stated above.

[Savoy54]

My '54 Savoy is a pain.  It always has been for the past seven years.  It's a hard start and after sitting hot for a while in a parking lot, it can be worse.

It has a rebuilt carb., Crane Cam Fireball ignition and a replaced exhaust manifold with functioning heat flapper.  It is has a two speed Powerflite tranny and power steering.  It turns over ok, but takes forever to catch.  The intake and exhaust gaskets have been replaced, it doesn't blow a blue cloud down the road, and when under power, goes well.  I just rebuilt the fuel pump as the old one crapped out.  The exhaust has been redone, so there is no restriction there.

The plugs, distributor cap and rotor are several years old and will be replaced, but it has always been about the same to start.  Any ideas where my issue may be?