Problem starting

[55 cadi]

Hello all,

I am having a small issue with starting my 55.

When it sits over night it doesn't want to start up, after a shot in the carb it turns over, I drive to store, about 30 minutes, come out and it starts and go home. Sometimes when I try to start after getting home it doesn't want to.

What may cause this?

Answers to questions.......
Carb was rebuilt, tuned.
Fuel lines done and tightened, except have not checked rear hoses into tank.
Fuel in glass bowl.

Now the two screws at base of carb were adjusted, but what about the center screw? I believe there is a screw between the idle and air screws, What is the setting generally at on that one?

Thanks for info.

Jason

[Roger Zimmermann]

How old is the fuel pump? Those pumps are placed in a such unfortunate location: they are getting all the heat from the engine and fail on a regular basis. You may just have some dirt in a valve from the pump, preventing the pump to function correctly.

[Jim Salmi #21340]

Roger:  He says he has fuel in the glass bowl.  Wouldn't that suggest that the problem is upstream of the pump?  I wonder if the carb needs more tweaks, or maybe accelerator pump is acting up.  Or something with the ignition.

If you pump the accelerator, will it restart then?

[55 cadi]

Thanks for responses

The carb was rebuilt recently.
The fuel pump is NOS, installed a few months ago.
After I drive and park, it will start with no problem usually restarting after about 30-45 minutes.

But when it sits over night it will almost start but not quit enough to run.

[35-709]

IMO --- if the fuel pump is truly NOS for a 1955 then the diaphragm is already old and no doubt brittle, or becoming so, plus, the old style diaphragm material in that pump is not going to last long with ethanol laced fuels.

[Mike Josephic CLC #3877]

Mr. 35-709 is correct.

If you installed an original NOS pump without having it rebuilt
that is a very likely culprit as the source of your problem.

The pump diaphragm after sitting on a shelf for 60+ years is
likely bad and will get worse.  Those are also, as pointed out,
not resistant to ethanol.  Take it off, send it to a guy like
Arthur Gould who will rebuild it correctly.

Mike

[marty55cdv]

  If it won't start when cold, make sure the choke is closing , rebuild or not,  also the accelerator pump on the car needs to squirt some fuel when you pump the gas pedal to set the choke.

[55 cadi]

I was afraid that being NOS that it may be a problem with the diaphragm.

This is a bummer being that this is my daily driver.

Is rebuilding that difficult to do?

[chrisntam]

get a replacement pump from Rock auto.

http://www.rockauto.com/en/catalog/cadillac,1955,series+62,5.4l+331cid+v8,1320770,fuel/air,fuel+pump,6256?a=Referer+www.google.com+URL+%2F

see if that fixes it, send your NOS out for a rebuild....

But you have another car, right?  the '55 is not your only one....If so, your's are bigger than mine....

[Roger Zimmermann]

I'm wondering if the Spectra pumps are better than the Airtex ones...

[55 cadi]

I have a new airtex filter on hand, guess I will try to get that one installed to have the NOS rebuilt.

[chrisntam]

Obvious man here, only have the NOS one rebuilt if the replacement pump solves your problem....

I hope it solves your problem, nothing worse than a non-dependable unit.

[55 cadi]

So......is it easier to just take off the fuel pump and install new one  or.......take off filler neck with fuel pump still attached and re-install same way with fuel pump already attached?


Thanks all the help
Jason

[CadillacRob]

Yes, it's easy to take off the fuel pump and replace it.

My personal feeling is that the pump is not your problem.  If the car runs fine once it starts then that sounds more like your residual fuel pressure is bleeding out when the car sits for a while.  This could be from anywhere throughout the fuel system.  Any rubber hoses or metal fuel lines/connections could be suspect.  Inspect everything thoroughly for leaks.  Rubber needs to be new and connections tight.

Carb is suspect as well.  Somewhere, fuel is bleeding down.

I've heard of guys adding an additional electric fuel pump for cars that sit around.  You turn it on before starting the car to re-pressurize the system, then turn it off and let the mechanical pump do the rest. 

To me, Id rather not alter things. 

Good luck and sorry I couldn't be of more help.  All I can say is, your problem is not entirely rare in these old cars. 

[55 cadi]

Thanks Rob,

The thing is that it turned over fine and then I did multiple things about the same time.....replaced fuel tank and hoses, replaced fuel pump and hoses, had carb rebuilt.  I knew better than to do all at same time, so if there was an issue I could pin point it easier.

So process of elimination now. I put new original style hose from farm to pump and lines from pump to filter and then to carb are tight, so will have to check the fuel pump out and maybe check the hoses at the tank to make sure those are tight.

[CadillacRob]

Yeah, get under there with a flashlight and run your hand around connections to ensure all is dry and tighten up clamps.

What I'd also do is remove your carb, and rest it on 2 bricks so that there's open space under the center of the carb.  Fill the inlet with fuel slowly until it pours out a little.  Now wait and see if fuel leaks down at all, in the center, where it goes into the intake manifold.  You can put a piece of cardboard under and see if it gets wet. 

Also, drain out all the fuel in the carb, put the inlet up to your mouth with the carb "closed" and blow hard.  It should not let any pressure leak through.  Should be air tight.  If it isn't, you have a leak.

[Maynard Krebs]

A 'rule-of-thumb' on starting / running issues used to be:  check electrical before fuel.

Original poster doesn't mention whether this car's starter always spins at the same speed.   If so, good.   If not, maybe the starter / relay / switch / battery... is a bit weak, esp. under certain conditions.

[55 cadi]

Hello Maynard,

The car turns over, how strong? I don't know,  I am charging battery over night today, in general when I get it turned over(prime carb) the car will restart on its own, just not a day later.

I retightened all the hoses tonite to see if I was getting a little air in the lines.

So I don't know if it's a combo of things or just one, but the process of ellimination is started.