Fuel routing. This can't be correct!

[Lawson Cox]

Originally Posted by mkcharlie

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

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.

[mkcharlie]

The ele pump is before the mechanical.

[mkcharlie]

Originally Posted by Lawson Cox

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.

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.

[petehoovie]

Originally Posted by mkcharlie

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.

[SoCalCoupe]

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.

Originally Posted by mkcharlie

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.

So yes, your proposal sounds correct.

[mkcharlie]

Sponsored Links (Register now to hide all advertisements)

Well. here it is Wed. Wife and I fighting bad colds, but snuck out to the garage - a little Sunday night, a little last night and by golly by high noon today, It's all re-plumbed. And it seems to be all good. Car drives great. Idles smoothly and seems to have better power too. The pressure gauge reads between 4 and 5 lbs but I don't know if it is really an accurate instrument so am going to have it checked with a professional grade instrument that my friend has to be certain. No leaks, no gasoline smell, life is good. Posting pic of the re-routed set-up. Thanks to y'all for your advice and help.

Now to work on the windshield wipers. I feel another thread coming on.....

[GB SISSON]

Vacuum wipers suck.....

[tomcarman]

Originally Posted by GB SISSON

Vacuum wipers suck.....

Much like the door to door vacuum cleaner salesman in a sales slump. Goes out for a drink with another door to door vacuum cleaner salesman. Asks his buddy, "how are sales going?" Buddy replies, "well sales lately have sucked but business is picking up." (insert groan here)

[petehoovie]

Originally Posted by mkcharlie

Well. here it is Wed. Wife and I fighting bad colds, but snuck out to the garage - a little Sunday night, a little last night and by golly by high noon today, It's all re-plumbed. And it seems to be all good. Car drives great. Idles smoothly and seems to have better power too. The pressure gauge reads between 4 and 5 lbs but I don't know if it is really an accurate instrument so am going to have it checked with a professional grade instrument that my friend has to be certain. No leaks, no gasoline smell, life is good. Posting pic of the re-routed set-up. Thanks to y'all for your advice and help.

Now to work on the windshield wipers. I feel another thread coming on.....