Technical Flat head won't start

I have a 53 ford Crestline with a rebuilt flat head. I put 2-2's on it. It has the stock fuel pump. After the car sits a week I have to prime the primary cabuartor every time.
Any suggestions on how to fix this?

 

so it does start , you just have to prime it?

 

Very typical.
Install a 1-3 lb in line electric fuel pump on a toggle switch. Turn it on to prime the carbs before starting then turn it off and hit the ignition switch.
Easy peesy, problem solved

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I would look it over real good. Check the fuel lines for leaks all the way to the gas tank. Check floats look for leaks on the carbs. Something is not correct. Did it do that before the intake swap??? If not then it's in the lines or the new carb set up. Is it vapor locking?

 

Also check your diaphram in the fuel pump. Iv seen gas tanks vapor lock up and **** the fuel back out of the carbs on wore carbs and pumps. Wore out float valves or dirty. You just got to get in there and get dirty. Good luck let us know what you find out.

 

Did you say prime the primary carb.? Meaning you have a progressive dual set up?
If so this could be part of the problem. Though it obviously starts if it doesn't sit too long.
Perhaps the bowl is draining .

 

OK, did not see mention of carb type. If you got dual 97's, cool, they shouldn't be leaking. If they're original Fords or 94's, there's a power valve inside the carb. The power valves included in the rebuild kits have a different or lack of taper to match the carb and will leak down with time. You can look inside the carb and see it leaking into the venturi.
I run a low pressure NAPA pump on a dpdt switch on-off-temp on. So can prime if need be or run all the time if the mechanical fails. I have never heard of a twin carb manifold with one as a primary?? Got pics?

 

As the guys said that is a fuel draining out of the bowl (s) issue an not a flathead issue. I've got the same problem with the 454 in my dualie. If it sets a couple of days it's a pain in the **** to start.

The parts houses sell a little Purolator cube fuel pump that will work to push fuel to the carb when you need it pushed up to start the rig and they don't seem to cause any restriction in the fuel line as I have had one on an ot truck for years for that same reason.

 

Yes it does start and runs great. But after it sits for 3 days it won't start unless I prime it

 

Modern gas evaporates instantly. If parked hot, the gas evaporates very quickly.

If you just start a car for a minute then shut it off, the cold motor will retain the gas a bit longer, but will still evaporate eventually.

I've been forced to run booster electric pump with a push ****on on cars that only get started weekly/monthly. 6 volt is worse as they don't crank as fast, to get the fuel back up to the carbs

 

Thank you everyone for your help

 

So does one install this electric priming pump before or after the mechanical pump? or doesn't it matter?

 

I do mine before the mechanical pump

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and the electric pushes fuel right past the manual one right up to the carb?

 

Yep. I had the same problem with my flathead and 97s. Put the electric pump back at the tank, pushes fuel all the way past the mechanical pump into the carbs. On a toggle switch direct to 12v. Prime it, turn off, start and run on the mechanical.

 

Try this link:

http://www.thecarburetorshop.com/Troubleshooting.htm#Hardstartcold

Jon.

 

Stock distributors don't work with dual carbs, no vac*** to advance and retard it, need to put a Bubba SBC Dist in it too.

 

All you have to do is drill a port. Guys have been running 2,3,4 carb flathead set ups since the 30s with engine pumps. I would find the real issue fix it and not byp*** the problem with an elec. pump. But that's just me...

 

The real problem is the fuel not the system. Modern fuel is made for sealed system Fuel injected cars with no vent to atmosphere. Evaporates as low as 135 degrees... It has a much lower boil off temperature. When you drive the moving fuel keeps the carb and intake cool (relatively) when you stop heat rises and begins to evaporate fuel...it's sometimes a double whammy because the fuel that evaporates out of the carb will condense in the air cleaner and drip down into the intake , which causes flooding.... hard or non start.... and also carbs are empty so once it does start, the bowl can still be empty and it will stop again...only to now be a lack of fuel...it can do your head in chasing the problem.
One thing you can do is fit a heat insulating gasket under the carb....
test this ... set up a tight fitting clear plastic hose from the air vent tube(s) to a cooled collecting condensor/container after you stop the engine hot...see how much fuel is forced from the vent.

 

Had the same problem with my dual 97 carbs, got rid of the stock fuel pump and put a nice big low pressure electric Carter back near the tank running off a relay through a regulator at 2 pounds pressure. Cleans up the engine nicely, never gives me grief and is over engineered to last a long long time. I use the old pump location to fill my oil now.
The setup that I like for distributor is the flatty MSD with 6A box, great curve built in and you could probably weld with the spark, no matter what, it fires first crank.