Fuel routing. This can't be correct!

mkcharlie

mkcharlie

Junior Member
Facts: Recently acquired '40 Ford w/ electric and mechanical fuel pumps with too much pressure to the carb. Notice in the pic attached the flow of fuel. Just follow the magenta lines with arrows from position marked "Fuel Tank" to the "Carb". Notice that the fuel comes from tank thru in-line filter into the mech. pump then out to the "out" connection of the regulator, then out the "in" port to the carb. (Dizzy yet?) With the ignition "on", turning the fuel pump toggle switch "on" without starting the car, the pressure gauge reads 4 lbs steady. When I start the car, the gauge reads 5-7 lbs.
Methinks this is routed wrong as the gauge is measuring the pressure before the regulator. I've also included a close up of the regulator (Holley) to show the markings.
Two questions: One, am I right and would a simple fuel flow re-route thru the regulator solve my problems?
Two, If, I wish to only use the electric pump, what else do I need to consider besides a block off plate for the old mechanical FP? Thanks
 

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mkcharlie said:
Facts: Recently acquired '40 Ford w/ electric and mechanical fuel pumps with too much pressure to the carb. Notice in the pic attached the flow of fuel. Just follow the magenta lines with arrows from position marked "Fuel Tank" to the "Carb". Notice that the fuel comes from tank thru in-line filter into the mech. pump then out to the "out" connection of the regulator, then out the "in" port to the carb. (Dizzy yet?) With the ignition "on", turning the fuel pump toggle switch "on" without starting the car, the pressure gauge reads 4 lbs steady. When I start the car, the gauge reads 5-7 lbs.
Methinks this is routed wrong as the gauge is measuring the pressure before the regulator. I've also included a close up of the regulator (Holley) to show the markings.
Two questions: One, am I right and would a simple fuel flow re-route thru the regulator solve my problems?
Two, If, I wish to only use the electric pump, what else do I need to consider besides a block off plate for the old mechanical FP? Thanks
Click to expand...

No picture. A picture WOULD help. Hard to follow, but is your elect pump before or after mechanical pump? Try wording this again, or maybe it's just me.
 
Lawson Cox said:
No picture. A picture WOULD help. Hard to follow, but is your elect pump before or after mechanical pump? Try wording this again, or maybe it's just me.
Click to expand...
Step by step;
1) Gas comes from Ele. pump underneath car -not in picture.
2) Comes up metal tube to the inline filter shown in picture.
3) Then enters mech pump. Pressure applied by mechanical pump and then out Mech pump.
4) Fuel then is sent to fitting with gauge attached to regulator's "out" port. Shown in picture and in closeup.
5) Fuel then is sent out of regulator's "in" port to the carb.

I'm suggesting that if fuel was sent to the regulator's "in" port, then out regulator's "out" port to the carb, peace would return to the land, butterflys, confetti, the whole enchilada.
 
mkcharlie said:
Step by step;
1) Gas comes from Ele. pump underneath car -not in picture.
2) Comes up metal tube to the inline filter shown in picture.
3) Then enters mech pump. Pressure applied by mechanical pump and then out Mech pump.
4) Fuel then is sent to fitting with gauge attached to regulator's "out" port. Shown in picture and in closeup.
5) Fuel then is sent out of regulator's "in" port to the carb.

I'm suggesting that if fuel was sent to the regulator's "in" port, then out regulator's "out" port to the carb, peace would return to the land, butterflys, confetti, the whole enchilada.
Click to expand...
504171


504172
 
Okay. Pictures help a lot. I do not have a regulator with my electric pump as I only use electric pump to prime the carburetor after the truck has been sitting for several days, say about a week.
 
Hard to tell from the picture, but it looks really toasted up.

That looks like a Holley fuel pressure regulator just like mine. Fuel from the pumps is going in to the "out" of the regulator. That's wrong. Out from the regulator should be out to the carb. You're measuring high fuel pressure because it hasn't been regulated yet, and it appears that the regulator is plumbed backwards.


I have a Holley fuel pressure regulator, fuel filter, electric pump and mechanical pump in my setup that's plumbed correctly. I'd be more than happy to work with you to straighten this out with more photos, Zoom calls, PMs, whatever.


it should be:


1. in from the tank to the electric fuel pump
2. out the electric fuel pump into the mechanical fuel pump
3. out the mechanical fuel pump into the "in" of the regulator
4. out the out of the regulator to the fuel filter
5. there are two outlet ports on the regulator, one should be out to the fuel filter and one should be out to the fuel pressure gauge
6. out from the fuel filter, in to the carburetor

7. the fuel filter could actually be at multiple points.


mkcharlie said:
I'm suggesting that if fuel was sent to the regulator's "in" port, then out regulator's "out" port to the carb, peace would return to the land, butterflys, confetti, the whole enchilada.
Click to expand...


So yes, your proposal sounds correct.
 
Last edited:
mkcharlie said:
If, I wish to only use the electric pump, what else do I need to consider besides a block off plate for the old mechanical FP? Thanks
Click to expand...


I THINK there's a problem with removing the fuel pump that needs to be addressed. Don't know what it is but smarter guys on this forum can tell you.



On the other hand, unless the mechanical fuel pump is leaking just leave it there. If the mechanical pump works, use the electric pump for priming only. If it doesn't work, get the mechanical pump rebuilt and use the electric pump for priming only.



You can use an electric fuel pump only but I don't see an advantage to that. The further you drift away from stock configuration the more problems you invite.
 
There should be a fuel filter between the fuel tank and the electric fuel pump. The filter and electric pump should be close to the rear fuel tank. Some electric pumps will not allow the fuel to be drawn through them by the mechanical pump. You need a solenoid type electric pump , not a motor driven one. 2 or 3 psi is enough for your Ford carb. Regards, Kevin.
 
Thank you gentlemen for your quick and competent responses.

To brother Cox who said; “ I do not have a regulator with my electric pump as I only use electric pump to prime the carburetor after the truck has been sitting for several days, say about a week”. That advice is consistent with my understanding of a purpose for an electric fuel pump. Thanks

To brother SoCalCoupe who said; “ I'd be more than happy to work with you to straighten this out with more photos, Zoom calls, PMs, whatever.” Thanks so much for your kindness. I think from your comments and those of the other responders, I feel comfortable in proceeding to re-route the “toasted up” present configuration. Cool phrase - “toasted up”.

To brother Koates who wrote: “ There should be a fuel filter between the fuel tank and the electric fuel pump.” There is, and it is in addition to the one visible in the picture. The ele FP is solenoid driven. Thanks.

Will send photo of the corrected set-up when completed.
 
Mkcharlie,
Welcome to the Ford Barn! Your fuel dilervery system is in good hands! I can barely do original equipment items. I did attempt to follow your information and pictures and flow path. In the least confusing. The guys that know way more about these add on systems are going to assit you through this.
I believe some of these add on components mask a problem with the original equipment. And then some of us like to add gadgets and things to try to make improvements over original equipment. Either way original or add on items, if not installed correctly, strange and unwanted things can happen.
By reading back through your posts, you have a good handle on these systems too.
Hoping things come out good and the 40 starts and runs good in the future. Now that you have posted some pictures, we do need some pictures of the car too! just sayin....
Regards,
Chris
 
I have found that with the proper electric pimp, there is no need for a regulator and the mechanical pump can pump thru the electric pump as needed. i use mine to prime and to run on the highway on hot days as needed. never a problem.
 
What's the point of the electric pump if not for priming or clearing vapor lock? I have no idea what the thought process is there. I'm not trying to be crass but I would ditch all that junk and use a mechanical pump. It worked in 1940, why wouldn't it work in 2022?
 
Using the Purolater Facet electric fuel pump eliminates the need for a regulator as it is solid state and is self regulating to the design pressure you purchase. Also, Teflon tape on fuel line fittings is not recommended as small pieces of Teflon tape can get into the fuel system.
 
A lot of dialog about the electric fuel pump without touching on the main issue.
It is generally agreed that an electric fuel pump should be installed as close to the fuel tank as possible. Electric pumps push better they. they pull.
It is recommended to install a pressure switch in the power source that is controlled by engine oil pressure to turn the pump off in the event of an accident
.AIRTEX makes a good 6v pump. I have used many electric pumps in my vintage cars, either as a primary system of just to starting after the vehicle has been sitting for many days. An added feature if the pump is close to the tank it is not effected by engine temp, therefore it can be used to break a vapor lock.
Looking at your picture leads me to believe that you are over thinking the whole situation.
 
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