1953 Ford flathead hard starting now

[CCruz]

I have had my 1953 Ford Sunliner with a flathead V8 since 1983 and I never had issues with it starting like this, now.  All the usual recommendations have been replaced: coil, points, condenser, plugs, rotor, etc.  Recently it went into the shop because it would grind and grind and never seem to turn over.  They rebuilt the carburetor, replaced the fuel pump and changed the ground.  Once the car starts, it runs and sound great.  But once I turn it off....

 

It will start fairly soon after I turn it off.  Wait about 15 minutes and it grinds and I have to open the hood and prime the carb with gas.  Once that gas catches and burns, it is like I am pumping the pedal like crazy to get gas flow!  It NEVER used to have this issue.

 

I lurked on this forum to see if anybody else had this same problem.  I noticed one comment about cleaning the electrical connections.  Did that.  Not much change.  

 

What else could it be?  I have boxes of replacement parts of the above items that were recommended but none of them made a difference.  

 

Sure can use some help from those who may have had this same problem!

[Matt Harwood]

You're likely experiencing what many of us with flathead V8s of all kinds experience--the fuel is boiling out of the carburetor during a hot soak. Temperatures under the hood skyrocket after you shut down the engine and air and coolant stop flowing. Add in the fact that today's fuels are so much more volatile than the old gas when your car was made, and you have the problem you're experiencing. It used to be that the gas was difficult to vaporize so automakers didn't mind the carburetor getting hot, but today it vaporizes at room temperature and the heat exacerbates this situation. The gas in the carb is literally boiling away and disappearing, often in just a few minutes. I've actually been driving my 1929 Cadillac and after parking it can hear the fuel in the carburetor percolating. The symptoms you describe sure seem like this is what is happening, especially since it will start quickly if you manually prime it. Once it's running, the mechanical pump is supplying enough fuel to keep things working, but at cranking speeds it's pretty weak.

 

The solution many of us use is an electric fuel pump that will combat the fuel boiling in the lines and prime the carburetor before you crank it. Some will recommend adding diesel fuel or kerosene to the mix, and this may help retard the boiling effect, but what is happening is that your carburetor is dry and you need to fill it back up to start the engine. The factory mechanical pump doesn't really move much gas at cranking speeds (50-80 RPM), which is why it may not refill the carburetor bowls without a lot of pumping and cranking. The electric pump will help a great deal in this situation. Put it on a switch so you can turn it off once the engine is running and let the car operate on the mechanical pump alone.

 

Hope this helps!

Edited July 31, 2015 by Matt Harwood (see edit history)

[Beltfed]

I agree with Mr. Hardwood, an electrical fuel pump wouldn't hurt. But then you said you've been driving this car for years and never had this problem. If you have not done anything to the fuel system and this problem cropped up...maybe you have a restriction in your fuel line. A replacement fuel filter might be in order. Crud in the gas tank blocking the gas supply?

I remember reading about a guy who was driving cross country with his brother. They stopped for a fill up and his brother added a fuel booster as the engine was running a little rough. Shortly there after the engine would shut off. After a short time it would start right up and run great and then shut down again. He found out that when his brother added the fuel booster the aluminum seal on the bottle had fallen into the gas tank. It would move around the tank, get sucked up to the outlet and stop the fuel supply. After setting the seal would float away.

[CCruz]

Interesting.  Never thought of the electric fuel pump. The rebuilt carburetor made a huge difference because prior to that it had tended to run pretty rich. Ironically this was the first time the carburetor has been rebuilt during the time I have owned the car. Now it runs and sounds good with the choke all the way in after it starts up. Recently I have had to prime the carb at least three times before it "takes."   In the past I have only had to prime it after it sat for some time but it usually started.  Yes, before now it never took much.  

 

Beltfed, I recently discussed this problem with a fellow who rebuilt a 54 Skyliner and he said to check the entire fuel line for some restriction/collapse and suggested replacement.  As I said previously, I have boxes of replacement items that never solved the problem so I don't really know if changing the metal line would be a solution.  The fuel pump bowl is full of fuel when I check it so I have been inclined to think it is something between it and the carb.  At first I thought I had an electrical problem because before the carb rebuild, priming did nothing.  The old car mechanic replaced the new coil and said it was defective.  

 

Starting the car after a day can give me a short start, ala priming, and then it grinds and I have to prime so at times it seems like it has a little initial fuel, but that isn't always the case.  

[JACK M]

The initial fuel comment made my light go on.

It could very well be that you have a leak in one of your rubber lines (I am guessing an air leak). The initial fuel would be what is in the float bowl and then you may be sucking air on start up thus running out of gas.

Rubber parts will go away without any visual warning. They can deteriorate from the inside and pull air without any sign of a fuel leak.

A fuel pump that is going away could very well cause the same symptoms.

[CCruz]

Thanks, Jack.  Now for the rest of the story!  Yesterday, after several hard starts, I decided to take the car to a car show/cruise night event in the center of town.  Took along some gas to prime it, knowing that was always an issue.  The 20 minute drive there was no problem.  After the event the car would not start.  It would grind and grind and once in a while catch from priming but would quickly stop after it burned that fuel.  Some folks gave me a push in hoping to pop the clutch.  Dd not work. As it turned out, one of the guys pushing also has a 53 Ford convertible and arrived late but did not register for the show.  Since he works at a local car dealership he offered to help.  He checks the points and also checked that I was getting a spark.  Then he checks the carburetor and noticed fuel was not being pumped into it.  We poured some priming fuel into the small throat tube and it finally caught enough to run.  He remarked that the fuel sending unit may be defective in the carb.  (Remember, the carburetor was professionally rebuilt by a reputable old car mechanic)  

 

I began the drive home and after driving a few blocks, it began to lose power and sounded starved for gas.  I pumped like crazy to keep it running, know I would be in deep trouble if it died at night and far away from home.  After about five minutes of this, it finally revved up enough that I once again had power and was able to get home.  

 

So, after this particular experience, it sounds like I have a real problem in getting initial fuel into the carburetor.  If fuel is not going into, then why is is able to generally get fuel when it is running?  (other than the one power loss incident)  

 

So, Jack, even though it has a brand new fuel pump, I would not discount the air issue, too.  

 

Ah, the frustration that  never used to have with this car!

[JACK M]

Try hooking up an alternate fuel source. Like the 6 gallon tank out of your neighbors boat.

With a little adapting you can hook it up in several places so you can eliminate areas as you go.

ie: fuel pump in, fuel pump out (use the primer bulb in the boat line), at the gas tank, you get the idea.

[Matt Harwood]

I'm still thinking fuel pump. Although it's new/rebuilt, that's no guarantee of quality and many of the rubber diaphragms used in these ancient fuel pumps are not methanol tolerant. Modern gas will eventually cause them to fail. Sounds like your pump is having trouble getting fuel moving at starting speeds and may be failing at driving speeds. Was the pump NOS or rebuilt? A rebuilt one may or may not have modern seals and rubber diaphragm, an NOS pump definitely will not. Try the electric pump thing and see what happens. It's cheap insurance and will be useful in the future for other purposes. It will also allow you to do some troubleshooting--if it runs fine with an electric pump then you know the mechanical pump was the culprit.

 

You might also want to check the power valve in the carburetor. These are apparently notorious for failures and I recently had a problem with a similar car (1955 Ford) and one of the issues was the power valve in the carburetor. I bet your car uses a similar carburetor (Holley 2-barrel).

 

Finally, I'd check the coil. Hot starts are tough on coils and they'll work fine when they're cold but start to falter when they're hot and it feels a lot like running out of gas. I picked up a brand new 6V coil for that 1955 Ford while I was on a long-distance trip at O'Riley's Auto Parts for about $30. Again, cheap insurance.

 

Your problem isn't a major one, and I'm still betting on the fuel pump being weak.

Edited August 2, 2015 by Matt Harwood (see edit history)

[cahartley]

It could even be piece of crap sticking one of the check valves in the pump.

Do you have a filter between the tank and pump?

 

Sometime immediately after you shut off the engine loosen the gas line at the carb.

Gas should still be under pressure and will squirt out.

If it doesn't you've narrowed things down to the pump.

Edited August 2, 2015 by cahartley (see edit history)

[DavidAU]

If you are going to fit an auxilary electric fuel pump for priming the carb and when you have suspected fuel boil etc., make sure it is one that the mechanical pump can suck gas through it when it is not swtched on.  

 

Some pumps wont allow fuel through them when they are not operating.

[Curti]

He remarked that the fuel sending unit may be defective in the carb.  I am curious about this. Is there another technical term for this?  Maybe fuel valve or needle and seat... or?

 

I run Airtex 8902 electric fuel pumps in my old cars. They will pump right thru the mechanical pump and if the Airtex should fail, the mechanical pump will pull gas thru it. They are low pressure 2.5 - 4 lbs. No special plumbing required. 

[Guest WEB 38]

Check for wear on your fuel pump push rod  A Common problem in the 50s on those engines a quick fix was to put a piece of foil in the fuel pump o top of the push rod to make up for the wear. Bill

[JWLawrence]

You mentioned that the mechanic changed the ground when doing the tune-up. This may be part of your problem if the coil leads were not sw aped when this was done. Going from positive, which is correct for your '53 Ford, to negative ground, in itself, has no added performance benefits. Don't know how your coil terminals are marked, but for a positive grounded system the positive marked terminal goes to the distributor, and vice versa for a negative grounded system. You coil may be marked "Dist" and "Bat" or something like that if it does not have "+" and "-" marks. I would change the battery back to positive ground, make sure coil is connected correctly, and repolarize the generator.

 

(o{}o)

[CCruz]

JWLawrence, yes, I questioned the changing of the ground as a solution.  He told me he had to change the coil leads and the voltage regulator leads.  

 

WEB38, another fellow mentioned the same thing regarding the fuel pump.  It was doing this with the previous fuel pump so that could mean the rod, IF that is the problem.  

 

Today, another guy I know said to check the sock in the fuel tank which might be causing a flow restriction with build up.  Then again, back to an earlier post, if the mechanic disconnects the fuel line to see if it is pumping fuel, that aspect could be eliminated.  

 

So far, no news from the mechanic!

[Larry W]

Today, another guy I know said to check the sock in the fuel tank which might be causing a flow restriction with build up. Then again, back to an earlier post, if the mechanic disconnects the fuel line to see if it is pumping fuel, that aspect could be eliminated.

So far, no news from the mechanic!

. A quick fix for that dirty sock is to use compressed air to blow back through the fuel line to dislodge whatever is clogging the pickup. Listen for air bubbles at the gas tank filler tube. This is only a temporary solution until the tank gets cleaned, but it's easy and cheap! Edited August 7, 2015 by Larry W (see edit history)

[CCruz]

Still in the shop and today we discussed some of the options.  The mechanic state it took several times, priming it, to get it started to get it out of the bay from nightly storage.  The electric starter was mentioned, along with fuel line replacement.  I suggested checking the tank screen sock.  They are wanting me to convert to 12V system but I am not in favor of that at this point and stated I have never had this kind of trouble starting that car until recently.  It ALWAYS started rather easily even when it sat for a while.  So, we'll see what they do, next.

[Matt Harwood]

Whatever is wrong, switching it to 12 volts WILL NOT fix any of it. It'll open up a whole new can of worms and introduce a hundred new variables into the system that's already got issues. If that's the solution your mechanic is suggesting, might I respectfully suggest a new mechanic? Guys who throw that particular solution out there do a lot of damage and rarely have answers that old car owners need. "Let's make this car into something I understand so I can ignore the problem that I don't understand."

 

Have you tried the electric fuel pump, even a temporary setup? All your symptoms are pointing to fuel delivery problems, particularly at starting RPM when the mechanical pump is at its weakest and after sitting when the fuel bowls have had a chance to drain down. If the tank and/or lines are clogged, this will at least eliminate one more variable and it takes about $50 in parts and 45 minutes of time and you'll have an upgrade that will help in the future even if it doesn't solve this particular problem.

[cahartley]

As soon as I read "change to 12 volts" I got one idea: Find another shop....... 

[Larry Schramm]

As soon as I read "change to 12 volts" I got one idea: Find another shop....... 

 

Absolutely agree

[JACK M]

Well, throwing an electric fuel pump at it is correct then?

Sounds like a band aid to me.

[Matt Harwood]

Well, throwing an electric fuel pump at it is correct then?

Sounds like a band aid to me.

 

I disagree. An electric pump for priming a carburetor makes old cars much easier to start. When you combine today's gas which evaporates at room temperature with cars that sit a while between uses, you end up with dry carburetors and hard starting, just as he describes. The Ford flathead's fuel pump is notoriously bad at pulling fuel at cranking speeds. When the car was new(ish), the gas wasn't nearly as volatile and the car was driven often enough that the carburetor stayed full and starting was relatively easy, even with a marginal mechanical pump.

 

The problems described here are exactly the symptoms of a dry carburetor and sluggish fuel pump. I'm not suggesting an electric pump in lieu of a properly functioning mechanical pump, but there are thousands of old cars (mine included) that run around with an electric pump running off a momentary switch which we can hold down to prime the carburetor or to give it a helping hand during vapor lock situations. My 1929 Cadillac can sit for six months, I turn on the ignition, activate the pump for about 5 seconds, and it starts as quickly as my fuel-injected modern car. Without it, I'd have to wait for the starter to turn the engine enough to build vacuum which would suck fuel out of the tank, pull it through about 16 feet of fuel line, and fill the vacuum tank sufficiently to have gravity push it through the filter and down into the carburetor. How many minutes of cranking might that take? How much wear and tear on the starter? How many dead batteries? How much coughing and sputtering before the tank starts delivering enough fuel to make the engine run properly? I have no idea; I use an electric pump and my car starts instantly every time, hot or cold.

 

Not a band aid.

 

Converting to 12 volts? Definitely a band aid. Worse, it's a band aid that does nothing to address the fuel delivery problem he's having.

[CCruz]

Yes, I nixed the 12 V system as an option.  I instructed them to check and or replace the fuel line and tank sock FIRST.  If that did not solve the problem, then check for push rod wear. I have been striving to keeping this car as original as possible.  

[JACK M]

When I go to start one of the cars that have been parked awhile I simply loosen the wing nut on the air cleaner and fill the dimple with gasoline and let it run down the stud. If the car fires I snug the wing nut, If it doesn't it almost never takes a third try.

I will NEVER use starting fluid. If it wont fire on gasoline there is something else wrong.

[CCruz]

I am not in favor of the 12V system because I never had previous issues in starting the car.  Something now, has changed, and I am confident it may be related to fuel delivery so they are probably going to change the fuel line and check the tank sock.  Do that first.  Check the push rod for wear.  THEN consider the electric fuel pump.  I am trying to keep this car as original as possible and right now I, too, do not see any advantage to a 12V system.    

[Larry W]

FWIW, isn't there a "fuel pump actuating rod" that rides on a cam lobe and actuates the fuel pump? Seems to me that I replaced this rod on my '49 Ford, as they do tend to wear down and get shorter, thereby affecting the stroke of the pump. It may be worth investigating. Larry W

[CCruz]

Finally!  The car is back from the shop.  Yes, it was there for a long time.  So far, she is starting fine.  So far.  So, here is what was finally done:  The mechanic replaced, under warranty, the new fuel pump.  That did not solve the problem and I was told they were thinking something electrical.  The fuel line had good pressure but as many of us suspected, the rubber hose from the fuel line to the fuel pump was leaking air!  This line was replaced.  They also found some loose wires on the starter switch.  Contact was intermittent because the nuts hold the wires on the starter switch were somewhat loose. 

 

I will run the car for a while and see if any of the old issues pop up.  Will report back!

[CCruz]

It has been over a month and I can happily report the cars starts fine.  This past week I started it after about a week of sitting and it didn't take much to get her going again.  So, THAT issue seems to have been solved.  Now....I will probably return the system back to its original electrical polarity.  The mechanic reversed it, back in July.

[Larry W]

I love it when a plan comes together! Thanks for letting us know how things turned out. Larry W

[dougy]

ok mines just opposite....wont start cold...im thinking same thing...fuel rod..or dry carb when cold...….what is purpose of fuel bulb...mine feels hard...and glass bowl is full.....but these don't hve accellerater pumps....so pumping would do nothing.....maybe weak spark????the flat head was put in not too long ago......anybody?????its in a 41 ford truck......maybe bad gas also??????sits long time...….tankis under seat......I like the idea of electric pump...….don't trust the mech. one...and push rod  being short