I tried to overcome a dry fuel bowl in my '46 pickup (original flathead V-8) by installing 1. a check valve down stream of the added fuel filter (one of those clear plastic filters, with fittings for the 1/4" line. The check valve is metal.)
2. an electric fuel pump installed below the level of the tank and parallel with the fuel line (like a rail road siding) and below the main line. This is switched so that I thought I could boost the pressure enough to fill the fuel pump above the block--it's a new one -- if /when the fuel siphoned downstream and left the carburetor without gas.

What do you old-timers suggest about keeping fuel in the line between runs and long sits in the very hot temperatures we're experiencing in the Midwest? There may be some vapor lock occurring.

The only method I've found is to pump 100 psi air into the filler tube until gas squirts into the clear glass bowl which is part of the fuel pump.

 

ejmaso

Just for what its worth to you there really is no such thing as vapor lock. Yes I know you hear it all the time.

Most common problem is you may have a tiny leak in the fuel line system that is allowing the warm air to enter on the draw side. You like many others myself included have in one time had the fuel pump changed, and the incorrect fitting installed.

Check to see if there are bubbles in the fuel bowl, the gasket under the glass may not be seated correctly, or it has a crack in it thus causing a tiny air intake. Gas is cold and its hot under that hood, hot & cold cause condensation. Further the fuel line on the bowl is higher than the bowl itself, so it can't flow out.

When you turn the engine over check to see if it is filling the fuel bowl on the pump, if not then check the above that I mentioned. This thing can almost drive you crazy at times its finding the leak that is the hard part. So start at the source, the tank, & make sure you gas cap is vented, if its an original then it should be okay, you don't want a tight fitting gas cap.

Check it all out and also make sure your check valve is hooked up to the correct way of the flow. Personally I don't know why you even have one of these on your truck, there not necessary.

Keep us informed as to your progress.

 

Thank you for your good suggestions about my fuel delivery problem in this '46 pickup.
I changed the old cork fuel bowl gasket for a new fiber one that seated firmly around against the beveled rim of the glass fuel bowl.
Also confirmed that the gas cap is an original loose-fitting (and thus air admitting) model. Tightened all the fuel line fittings in my overly complex adaptation of the electric fuel pump as a potential primer of the fuel stream in its 1/4" line.

Cranking the engine still does not draw up a column of fuel. I had removed the hose connecting the exit of the fuel pump to the carburetor inlet, so I could see whether the pump was delivering spurts of gas. Putting my thumb over that open hose end didn't make any difference in the fuel delivery, which was already evident in the empty glass fuel bowl.

The potential leak-point is getting harder to chase. I'll keep trying. Since I've got that check valve downstream of the fuel filter, maybe I could prime the system by squirting some gas back down the connecting hose, but you all who know these fuel pumps may already discount that plan because there's possibly a one way valve internally in the fuel pump.
I'll appreciate anyone's comments and suggestions.

 

ejmaso

When you installed the new bowl gasket did you lubricate it first, with oil? Then when you put on the bowl, you have to turn it back and forth just to seat it properly.

When you took off the line going from the fuel pump to the carb, while turning the engine over did it pump out gas? If none of this works then you may have a bad fuel pump, or a blockage in the line.

You don't need that inline check valve, get rid of it. As far as the fuel filter goes have you got it installed with the arrow pointing to the front, not trying to be comical here it some times happens.

You mentioned you had an electric fuel pump, turn it on and see if the bowl fill up with gas, it will work with the mechanical pump in place. If this works, then you have either a bad fuel pump the mechanical one or a blockage in the line some where. Besides there is absolutly nothing wrong with the cork gaskets but they have to be lubricated before installation.

If all this fails take off the fuel pump and check to see if it is loose I mean in travel where the push rod goes, this has to have very minimal travel the less the better. Also if your fuel pump has been rebuilt lately it may have bad fuel pump valve, some of the later ones rotted as they are most likely off shore ones.

If your fuel pump isn't working as it should I would suggest a complete rebuild kit, there not that much but get the full kit, and ask where you buy it from if they include the good valves. Try Mac's in Lockport, NY, or Carpenter.

Let me know how you make out with the above. I'll scan a diagram and post it so you can see what it looks like inside.

 

ejmaso

Here is the diagram I mentioned above that I would post.

 

I removed my mechanical pump and have had no problems with fuel delivery. BTW, the plate to plug the hole on the side where the fuel pump sits is the same one as for a 350. Mine is even chrome...

 

i may have the same problem i have an elect pump the fuel drains back to the tank? and its then hard to start or cranks to long befor starting.
so i turn the key and let the pump fill the carb take 15- 20 sec then it fires wright up

 

Schoo

This is a common problem with the Flatheads, its not the fuel draining back into the tank, but the Carb leaks the fuel into the intake, and there fore the bowl in the carb is empty, and needs re-priming.

I have the same issue and I've owned quite a few Flathead Fords. I always turn the engine over a few times pump it then turn on the switch pull out the choke and away it goes.

 

yea that sounds wright mine starts wright up with fuel in carb!
roy

 

schoo

If you really think about it, how could the fuel drain back into the tank. Its gravity fed into the fuel line, its only the pump that brings it up to and then fills the carb bowl.

Now if the fuel bowl at the fuel pump is not full then there is a seal issue, due to improper gasket seating or an inproper line connection or a pin hole some where in between. One sure sign of this is air bubbles in the fuel Pump glass bowl, and this is caused by drawing air.

 

well i have had some fuel leaks at a conection under cab
need more time away from my f250 for this truck she is a little lonely out side in the sun!
roy

 

[quote=5 Star;12111331]ejmaso

When you installed the new bowl gasket did you lubricate it first, with oil? Then when you put on the bowl, you have to turn it back and forth just to seat it properly.



You don't need that inline check valve, get rid of it.[I did that] As far as the fuel filter goes have you got it installed with the arrow pointing to the front, not trying to be comical here it some times happens.

You mentioned you had an electric fuel pump, turn it on and see if the bowl fill up with gas, it will work with the mechanical pump in place. If this works, then you have either a bad fuel pump the mechanical one or a blockage in the line some where. Besides there is absolutely nothing wrong with the cork gaskets but they have to be lubricated before installation.


>>>5 Star's advice is right on the money. Lubricating the gasket and ensuring a tight fit restored enough pressure to fill the bowl. My delay in thanking you was partly from struggling to resolve an ignition problem:

My Flathead was not firing on all cylinders. After noticing a weak spark at the plug wires, I suspected the coil. The new one throws a strong spark to from the tower terminal to ground but that replacement did not restore easy starting and running.

I unfastened the distributor assembly (base and cover--the kind with two rectangular "ears", rather than the clam-shell type) and inspected the connections from the stranded copper wires to the cups within the (almost new) cap. (I did not see any tell-tale evidence of arcing in there, but the black phenolic (?) is not easy to read.) Some of the ignition wire caps were distorted and so I replaced them with the same type of brass fittings. Result: no improvement on spark at the plugs.

Were some of the ignition wires leaking voltage inside the metal "loom"?
I replaced the wires with a set of Ford-made noise suppression wires, which had the advantage of really well seated caps, and the potential deficit of being slightly bigger in diameter---there's not enough room to fit 4 or 5 wires through those rectangular ports, and the receiving cups do not clinch the wire with a convincing "click". I ended up using a Dremel grinder to widen and smooth out the passage; there still wasn't enough room to get the cover seated. So I made a 1/4" spacer and re-made the two clips and lengthened the bail. I finally re-assembled the whole business and confirmed continuity to all terminals--on the bench.
After wrestling those two loom-pipes in place and checking for spark at various plugs, I had lost spark at # 1 and 2. Both of these wires within the distributor are next to each other right at the entrance point of the passenger side "ear" of the distributor cover. Perhaps the caps were pulled back during installation, just enough to lose contact with the cup and thus the terminal where the rotor passes. (By the Way, the terminals were not scorched/ degraded and the rotor tip looked good.
So, the only part I haven't renewed is the body of the distributor. It looks to me that there's a wire connection problem rather than a flawed distributor body, but that's where my attempted repairs have stopped, and now I'm hoping for some wisdom from the Enthusiasts.

All for now,

 

ejmaso

Which of the 2 pictured distributors are you using? I don't think its the top one but is it the same as the bottom one, or different?

These aren't that difficult to take off and to replace. There are only 2 bolts if its the bottom or top. If it has 3 bolts then its the earlier one which is a pain in the butt. Suggestion for what its worth and not out of being original, as the top one was used during the War years. Reason being as you look at it the wires were easier to change, without pulling off a bunch of caps.

You can't put these distributors on wrong as the key was is offset to the Camshaft, and will only go on one way. Speaking for myself I prefer the top one, even though I have the leter one on my Truck now. If for some reason it gives me trouble then I have the top one for replacement.

From what you have told me sounds as though tou have possibly messed up the one tou have on there now, by enlarging the holes. The wires that were meant for these Distributors were solid core wires. Also I seen it happen that the plate where the points are mounted somethimes fround out, sounds like you had better take off the Distributor and give it a thorough check.

 

Five Star,
Mine's the bottom type. Is the "crab type" so called in the D. Carpenter catalog, inter-changable with the round type (internal connections)?
In my Dremel work on the old cover, I did not enlarge any of the socket fittings. I just enlarged passage ways to get a little more room for the new ignition wires and crimped connectors.
Yes, it's time to take her out again. Would you recommend unbolting the whole assembly (two bolts) or just the plastic part?
Thank you for these tips and information.

 

ejmaso

Your right on it being called the Crab Cap, as it does in appearance resemble a Crab.

As for taking it completely off the timming cover via the 2 bolts, yes then you will be able to better check out the Distributor and see if there are any concerns. It most likely hasn't been off in quite awhile so now is the time to do so, instead of on the side of the road.

there is a special tool for setting the points and timming of the distributor, I will post it here for you to take a look at it.

Your Distributor could be a Malory which had dual points and this tool comes in handy. Another item to look at is the condensor make sure it is in good working order. We used to load them up and toss them to a friend, of course he would naturally reach out to catch it. Once he touched the wire and the condensor body, he may or may not still be your friend as it was like holding on to an electric fence wire, if you have ever been there.