fuel flow problem?

[Billmc52]

I am a new Model A owner having acquired my father's 1928 Phaeton in Sept. At that time I put on a rebuilt Zenith carb., new gas shut off valve with screen, new fuel lines and a new glass sediment bowl with micro filter to replace the cast iron sediment bowl. My driving has been limited to my neighborhood and only 3 to 5 miles at a time. The car has idled fine and run fine. This weekend I took it out for longer runs on Sat., 25 miles, and Sun. 12-15 miles. Ran fine, 50 mph, with no problems. However on both days after returning home and going back to the car within 15-20 mins. to ride some more, we had a problem both days. Car started fine, idled fine, but would not accelerate. Backfiring, sputtering, like it was not getting gas. Would idle fine, would not run when accelerator applied. After resting for an hour or more, back to running fine. One thing I noticed was that the glass sediment bowl had air in it, about a fourth of the bowl had air, and when I turned the fuel vale on, the bowl slowly filled. I may have multiple problems. Where is the gas going from the bowl? No leaks between gas tank and carb. Why the rough running after I have driven for some time, but after resting for an hour or more running fine? Even removed gas cap and still had problems. Should I clean cast iron sediment bowl and put it back on in place of glass bowl and micro filter? All advice and suggestions appreciated.

 

[Glenn C.]

You should install a fuel filter in the tank valve. Check to be sure the fuel line does not protude to far into the carburetor or sediment bulb. This can restrict the flow.

 

[Billmc52]

Thanks Glen, there is a screen on the valve in the tank. I'll check flow, but the problems only appeared after it had been running fine for many miles.

 

[31Tudor]

When you seem to be having a fuel flow problem, remove the gas line from the carburetor and see what kind of fuel flow you have to the carburetor. Then you can move back to the filter and then to the tank to try and identify where the restriction is.

 

[1930artdeco]

Is it possible that there is just enough sediment in the tank to cover the screen and restrict flow? Then after a little time it falls aways from the screen?

Mike

 

[Glenn C.]

We've got to remember, hardly nothing ever occurs until we want to use our cars, then all these agrivating problems occur.
If your screen is clean and every thing is clear, that sediment bowl should fill very quickly.

 

[HARLEYJOE]

You may want to check the float and valve inside the Carb..
Just because it is rebuilt does not mean it is set right
or problem with float valve.
Good Luck and let us know what your findings are..Joe

 

[Billmc52]

Thanks for all the suggestions. Should the sediment bowl be partialy empty after I shut off the fuel valve or should it remain full even with the valve closed?

 

[Billmc52]

You may want to check the float and valve inside the Carb..
Just because it is rebuilt does not mean it is set right
or problem with valve.
Good Luck and let us know what your findings are..Joe

Thanks. Would sticking float valve cause the sediment bowl to partialy empty when fuel valve is shut off?

 

[Glenn C.]

When you shut the fuel valve with the engine running, the sediment bowl will partialy drain. That's really what you want it to do when shutting the engine down, or am I missing something here ?

 

[Mitch//pa]

read over this stuff very valuable information::::::::

 

[Bruce Adams]

The micron filter is much to restrictive than needed and may be blocking fuel flow.
It also assumes a fuel pump and may not function in a gravity situation.

 

[Billmc52]

Thanks for all the info. I talked with a local car restorer this afternoon and he believes it is rust or some other debris in the tank. I've removed the carb and he is going to break it down and check and clean it. I'm also replacing the glass sediment bowl with a cast iron one that he had from a previous job (with a new screen). This weekend I'm going to drain the gas tank and flush and clean the tank as best as I can, then go back with a new screen on the shut off valve. When I pulled the carb off, I checked the fuel flow, and while it appeared alright, it did vary in volume some. I think the problem is going to be in the carb, restriction at the sediment bowl filter and possibly also sediment on the screen in the tank. I appreciate all the advice and will let you know the result.

 

[50B]

read over this stuff very valuable information::::::::

Is this little booklet available = WHAT TO DO IF THE MODEL 'A' STOPS, By Reidar Lohne

 

[CWPASADENA]

I'm also replacing the glass sediment bowl with a cast iron one that he had from a previous job (with a new screen).

Personally, I like the glass sedement bowl so you can see what is going on. There is a screen in the top of it to filter the gas as it goes out. I also think there is a filter element that is available that will fit inside. This seems like a good idea to me.

My opinion,

Chris

 

[Mike V. Florida]

Personally, I like the glass sedement bowl so you can see what is going on. There is a screen in the top of it to filter the gas as it goes out. I also think there is a filter element that is available that will fit inside. This seems like a good idea to me.

My opinion,

Chris

I agree.

In the tank you can place just an 3/4 inch of fuel line to raise the intake to above the rust.

Also if you feel the need for additional filters select one used for motocycles that have gravity flow.

 

[Mitch//pa]

Is this little booklet available = WHAT TO DO IF THE MODEL 'A' STOPS, By Reidar Lohne

save it to your computer and print it out

 

[1931 flamingo]

You could also try placing a few magnets (strong ones) on the bottom of the fuel tank (on the underside NOT inside). JMO
Paul in CT

 

[Paul from Maine]

Try it without any filters in the sediment bowl or the fuel line with the gas cap loose. If it runs fine, tighten the gas cap. If it doesn't then you need a vent. then add your filters one by one. It sounds like a fuel flow problem.

 

[Jerry Parr WI]

How do you define vapor lock?

I keep forgetting Model A's don't vapor lock.

When it acts up try increasing the speed gradually, using the choke if necessary. The engine compartment temperature increases dramatically when the engine is turned off. If this is the problem the engine will smooth out and start running again when cooler gas from the tank reaches the carb. The wait before restart allows the engine to cool down.