Fuel Flow Issues ???

W

wv raven

New member
Hello!

I have a 31 AA that has infrequent fuel flow problems in the Fuel Filter. The gas tank has been cleaned. When disconnecting the fuel line that leaves only the Peacock & Fuel Filter only, it flows well. When I have everything connected; the fuel amount in the fuel filter varies when the vehicle is running. The problem is when the truck is idling; it eventually runs out of fuel in the fuel filter and naturally the engine stalls. If the truck is idling and I rev the engine, fuel amount does increase in the fuel filter.
So; what is it that I’m asking? Better consistency fuel amount in the fuel filter to prevent from engine stalling, acting like it’s out of gas. Could it be a “push back” air issue in the fuel filter & line coming from the carburetor? BTW, I’ve tried several different aftermarket fuel filters including the FRAM Fuel Filter recommended from Bratton’s.
SUGGESTIONS?
I know I don’t have the correct late period carburetor for my model AA but that’s irrelevant.

Thank You folks for your time.
/Jeff
 

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A lot of those type filters are designed to work with a fuel pump as opposed to your application which is gravity fed.

Look for one that is used on lawn mowers.

Hopefully, Someone will come along with a part number that applies.
 
I see the coil wire cover isn't pushed onto the coil tower. Model A's didn't come with any coil wire covers, and I've seen them actually trap water and short the spark to the primary terminal. The coil wire will stay in place fine without the 2 covers for the ends,
 
WV,
Could your fuel line possibly be too long, at the carb, & touching the carb filter?? Some carb filters are the "MICRO-FILTER" type & can plug up with even the finest particles, which would pass through the carb passages & jets, with NO problem. Best to use the screen type filters.
Bill W.
 
I only use the ones that came with the A plus a pencil type filter ahead of the shut off that goes in the tank...
 
That filter is in absolutely the worst place! Directly across from the radiating heat from the exhaust manifold turn. That radiant heat (especially when stopped and idling) will make modern fuel cross the liquid/vapor point at the very low gravity head pressure there. The fact that there is turbulence and a very slight pressure drop across the filter provides the nucleation triggers for this to occur at that point. I dare not use the words "vapor lock" because that would re-open a can of worms!

You could try a reflective heat shield between the two points, but that would be big and ugly. Your filter, being clear, permits infrared radiation to penetrate directly into the filter and heat the fuel at the filter surface.

The original indented firewall carb had a side-bowl separator and screen with a bottom drain. It worked very well and being at the carb level it eliminated the problem of a heat sink and pressure drop right by hottest exhaust manifold point. You could get a correct sidebowl Zenith, but they are very $$$.
 
MikeK said:
That filter is in absolutely the worst place! Directly across from the radiating heat from the exhaust manifold turn. That radiant heat (especially when stopped and idling) will make modern fuel cross the liquid/vapor point at the very low gravity head pressure there. The fact that there is turbulence and a very slight pressure drop across the filter provides the nucleation triggers for this to occur at that point. I dare not use the words "vapor lock" because that would re-open a can of worms!

You could try a reflective heat shield between the two points, but that would be big and ugly. Your filter, being clear, permits infrared radiation to penetrate directly into the filter and heat the fuel at the filter surface.

The original indented firewall carb had a side-bowl separator and screen with a bottom drain. It worked very well and being at the carb level it eliminated the problem of a heat sink and pressure drop right by hottest exhaust manifold point. You could get a correct sidebowl Zenith, but they are very $$$.
Click to expand...


What you're saying makes a lot of sense.
Will this do the trick? http://www.mikes-afordable.com/product/A9155L.html I will still have my Peacock and Bowl too?
/jeff
 

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It could be a fuel tank venting problem. Try removing the gas cap, to see if the symptoms change. If it flows better, either the gas cap "vent" is clogged, or it might be a radiator cap (not vented).
 
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