No Start!!!!!

[Chris B.]

I have a problem with my carb. When my 35 -21 stud sits for more than 1 week, its seems that the fuel in the carb drains back down . I can turn it over and over with mayby a slight fire but no start. I can pump and pump but to no avail. After pouring just 1 or 2 ounces in top of carb, she starts right up. I ran out of gas once and had to take the top of carb off and fill bowl before it would start. Am I missing something here. Is there a reason why the fuel might be draining back out?
Any expert thoughts would be appreciated.
Thanks
Chris

[ford1]

two places it can go from the carb, thru the power valve if you carb has one, or passed the plugs you use to get to the jets, you need ken ct for a more xpert answer, the other place is the check valve flapper in the fuel pump is bad and letting the gas run thru the fuel pump back to the tank, the valve im talking about is the one in the pump that opens so fuel can be suck out of the tank and sent to the carb, if thats the problem you can either turn that flapper valve over or just rebuild the pump, i would susgest you install an electric pump in the fuel line, put it as close to the tank as you can, hook it to a switch so you can turn it on just long enough to fill the carb

[Lawson Cox]

I too would suggest an electric pump just to prime the fuel pump and carb after it has been sitting for a while. Read that, couple of days.

[Flathead Fever]

My understanding is there are different types of electric fuel pumps. Some of them will close when they are turned off to hold pressure in the system. If your going to install one just to prime the system it needs to remain open when there is no power applied to it so the manual pump can suck fuel through it. You should be able to blow through the pump when it is off. I do not know this for a fact, I was told this by someone who usually knows what he is talking about and it makes since to me.

Installing the electric pump will prime the system in a hurry but you still need to find out where the fuel is going when it sits for a few days and also why your manual fuel pump is not priming the system. The car should be able to set several days and then start without killing the battery and melting the solder out of the starter (never crank a starter more than 15 seconds). When your car was new it ran correctly without an electric fuel pump so all your doing by installing an electric fuel pump is masking a problem without actually repairing it. With that said, installing an electric pump is not a bad idea because it serves as a backup pump
If you do install an electric pump try to buy one that is the correct pressure so you do not have to install a fuel pressure regulator which is just one more thing that will leave you stuck on the side of the road.

Jerry

[ken ct]

Flathead fever is pretty much on the nail head. Elec. pump is just a bandaid. Fix the problem and you wont need an elec. one. Its either the valve in the FP. or the PV in the carb is not sealing.Neither one is easy to change for a newbei.Is this a stromb or a ford carb. It could also be a poor starting procedure on your part. Your constant pumping dosen't help. You could be flooding it right off the bat.Try just 1 pump and let up on pedal and try and start with your ft. off the pedal and give gas ONLY when it starts.Flats flood easy. ken ct.

[G.M.]

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The valves in the fuel pumps didn't work very good when the pumps are new. Put a low pressure gauge in the line between the pump and carb. Run the engine and check the fuel pressure and the pressure should vary between about 3/4 and 3 1/2 lbs. This depends on how good your needle valve works and how good the pump is. A lot of needle valves both rubber tipped and plain steel don't operate smoothly. You can see this on the gauge or on a Stromberg running with the top cover removed. If the valve works properly the pressure will stay around 2+ lbs, the needle on the gauge will just wiggle slightly and if watching the fuel level with the top off you won't see much of a change. With a sticky valve as the fuel bowl fills and as the valve closes you can see the pressure riseing on the gauge until it reaches it's high of 3 1/4 lbs. Now the valve sticks for a few seconds and the fuel in the bowl go's down and all of a sudden the pump pressure pops the needle valve open and the pressure drops on the gauge to maybe 1/2 lb. It don't drop to zero because the .098 restriction hole in the needle valve keeps a little back pressure on the line where the gauge is. As the bowl starts to get filled and the needle valve starts closeing the the pressure climbs to it's high of 3 to 3 1/2. Now the cycle repeats it's self. Watch the fuel in the bowl you can see this. Uncle Max has double ball needle valves that don't act this way, the small ball is subject to and works with very low pressures and pushes against the larger ball that seals the flow. The result is very small amounts of fuel constantly entering keep the fuel level with in a 1/8" verses the 5/8 to 3/4" movement with most needle valves. The gauge with the double ball just quivers slightly. Look at the Ford service bulletins on testing a fuel pump it says when you shut the engine down the valve pumps should hold the fuel pressure for at least 2 minutes before dropping to zero. This means they don't hold the fuel in the pump even when they are new. [email protected] Bob Shewman makes 2 types of flex hoses made of space age materials that the new gas doesn't effect and are gauranteed 5 years. One modle is a plain replacement hose and the other has a check valve built in the pump fitting of the hose, this check valve keeps the fuel from draining back out of the pump and make for easier starting after sitting for days. He make these for all years from 32 to 57. A lot of these starting problems posted on this forum are flex hose related. The old hoses are effected by the new fuels and on a lot of them you can feel the hose and it is soft and soggy. After removeing they get hard. These hoses suck a very small amount of air into the pump and the pump become very ineffective or don't pump at all. Priming the carb will usually get the running. This condition can change because the hose is soft and conditions change. The problems is it is hard to find because the fuel is not under pressure in the flex hose so you don't see a leak, it just sucks air in. I have used the double ball valves for 25 years and never had a problem since. And after a rash of hose problems went with Gadgiteers hoses and no more problems in that area. I have never needed an electric fuel pump in several hundred thousand miles in mostly 85 plus temperatures. G.M.

[01aford]

I agree with Ken CT. Sounds like the PV if it's not a Stromberg. I would start with the PV. I've heard that Ken has PV that work great and I know his fuel pump kits are very good I have 2-3 from him.
I would rebuild the carb with and new PV and the fuel pump..
No I don't have stock in Ken's business. He's just a good guy to work with and has good stuff not China crap....

[ken ct]

Thanks for the good words 01aford. Stroms have a PV in them also abit diff from a ford one. Some of them go bad once in a while too and leak.If you fix the problem you dont need all this hokess pokess stuff on the market nowadays there like the snake oil of yester year all kinds of peddlers for that junk and plenty of suckers out there that buy them. OMO. ken ct.

[Flathead Fever]

I thought about this subject a little more and I have a couple more suggestions. You have two separate symptoms, a carb that looses fuel and a pump that at cranking speed won't fill the carb back up. I‘m pretty sure you have two separate problems.
First, as far as the carb loosing fuel, there are only two places the fuel can go. If it sits too long it can evaporate out of the bowl. This can leave a varnish in there that can cause the needle and seat to glue its self shut and not allow any fuel to flow into the bowl when you go to crank it. I used to have this problem on some of the GTE/Verizon trucks that were not being used. They would sit for months between services and the needle and seat would get stuck in the closed position. Someone would have to tap on the carburetor next to the needle and seat while someone else cranked the vehicle and then they would usually fire right up. Since your vehicle is not sitting for months this is probably not your problem.

Second, the fuel leaked out of the carburetor and ran down inside the intake. This could be caused by a faulty internal part, gasket or even a cracked or warped carburetor. I have seen carburetors crack and warp but I have never heard of it being a problem on an early Ford Carbs. If I suspected the carb was leaking I would remove it and fill the bowl with fuel to the proper level and then see if any fuel leaks out the bottom of it, then you can see exactly where it is coming from. These early Ford carbs are nothing more than glorified lawn mower carburetors. If you can fix your toilet bowl float your probably qualified to rebuild one of these carburetors. Just don't over tighten anything, snug the little screws down evenly and when they stop turning STOP TIGHTENING THEM! I hate working on carbs that someone else has worked on, usually half the screws are stripped out.
As far as the fuel pump not priming the system. There are check valves in the fuel pump. The inlet valve will open on the vacuum stroke to let the fuel flow into the pump then it closes on the pressure stroke so that the fuel is pumped to the carb and not back into the tank If one of these check valves were to go bad and stay just slightly opened, at slow cranking speed the fuel might just get pumped back into the tank. With the engine running the pump would be moving more fuel and not all of it would be able to flow through the slightly stuck open check valve so the engine gets enough fuel to run

A couple of other issues The old cars had rubber hoses with woven cloth coverings. If your restoring your car this is the look your going to want. I had a ‘57 T-bird that my mother had bought brand new, she had it for two years and then traded to my grandfather for a small house. In the seventies he started worrying he would not be able to get parts for it so he went down to Ford and ordered every rubber part you could possibly think of for the car and stored them in air tight peanut butter jars. Around 1988 he died and I inherited this low mileage original paint ‘57 T-bird that had not been started in about ten-years. I rebuilt the original holley carb, installed a new fuel pump but I could not get the pump to prime the carburetor. If I filled the carb up with fuel it would start and drive all day long. If I let it sit for a couple of weeks I could not get it started again with out first filling up the carb bowls with fuel.
Here is what I eventually found. You always need to check the rubber fuel lines between the tank and pump for cracks. At one time or another we have all gotten straws with cracks in them, what happens when you suck on the straw, nothing, no fluid comes up the straw, all you get is air. Your fuel pump works exactly the same way. My ’57 T-bird had a short piece of hose at the back of the tank and one of those woven cloth hoses at the fuel pump. It was a strange little hose with factory brass fittings crimped on each end. I removed the hose and soaked it in dish washing soap and blew through it. Bubbles came out of the cloth the entire length of the hose, there was my problem, the fuel pump was sucking air. I wanted to keep this car absolutely original and fortunately for me my grandfather had bought a new fuel hose and store it in a peanut butter jar (he must have eaten 55 gallons of peanut butter a month) I pulled out this NOS hose with its nice original Ford part number tag still wired to it. It looks just like it was made yesterday, nice and flexible, the brass fittings had not even tarnished. I stuck it on the car and I have the same exact problem. I pulled that NOS cloth fuel line off and poured dish soap over it and blew into it, same thing bubbles from one end of it to the other. I can’t tell you how many time I have installed bad new parts, it screws with your head. I would have thought that there would have been fuel dripping from both of those hoses but if never showed any sign of leaking. The problem with those cloth hoses is you cannot see what the rubber looks like underneath. If you have to use them for a 100 point correct restoration, I would replace them every few years.

Another thing to consider on flatheads is the fuel pump mounting stand. The bases warp on them and this reduces the stroke of the fuel pump rod. I have no idea what the stroke of a flathead fuel pump rod is but lets just say it‘s a 1/4 inch. I have bases with an 1/8 inch warp in them, in fact 90% of them have 1/8 inch warps in them. it’s really hard to find a stand with a nice flat base. The fuel pump cam lobe could also wear and reduce the stroke of the fuel pump rod. I would check the base of your fuel pump stand to see if it is warped and while you have it off measure the travel of the fuel pump rod.

I bolted to fuel pump stands together and took a picture so you can see how bad they warp at the base.

Jerry

[Chris B.]

Thank you all for your valuable comments. especially Flathead Fever. My fuelpump tower may be the culprit as the threads holding the fuel pump are partially stripped and don't tighten well. I'll replace it. The fuel pump and rod are both new and the carb has been replaced but if new tower doesn't solve problem, I'll change PV.

[BIG MIKE]

Hey that happens to me everytime i Turn her over for 20 sec's waiting for the fuel to pump up . I'm not getting fuel in so i put a few ounces in from a beer bottle and She runs!! granted I only go out 2 times a month with her. Cheers BIG MIKE

[Ross in East Texas]

When starting my '39 after it had set for a few days I would have to crank it long enough that sometimes the battery would go flat, or nearly so. I got to where I used to take the gas cap off and blow in the tank. Just a few seconds of holding pressure on the tank and I could then start the engine. I finally put an electric pump on it so I could fill the fuel system before I tried to crank the engine.