electric fuel pump too powerfull

[bluefoxamazone]

I see that my electric fuel pump that I use for priming is exceeding the max presure and it overfills the carb. (it pushes 0.4 Bar= 5.8 psi)

If I would install a pressure regulator inline would the mechanical pump still be able to draw the fuel from the tank through the electrical pump AND the regulator? or is this a no go?

Thanks for the input!!

 

 

[desoto1939]

The first question is are you using the electric pump and also which model pump, to just act as a priming pump or are you leaving this pump on after the fuel has reached the carb.

Sounds as if you are leaving the pump run too long and is the engine running when the electric pump is pushing fuel to the carb?

I use an Airtex electric pump just to prime my carb and let it run till the bowl has fuel in the carb and also fuel filter, so say about 30 Seconds. Start the car with the pump running keep gas moving then I shut the electric fp off with a toggle switch.

I do not see why a fuel regulatory would affect the mechanical FP.  Some of the more experienced guys might have more input.

 

Rich Hartung

[Plymouthy Adams]

depending on the accuracy of your testing gauge you may or may not have a problem...at 4 to 5.5lbs  specified and the max pressure you display is 5.8 lbs, you just .3 high....however, if this is causing flooding by over pressuring the inlet needle/float within the seat...you could install a pressure regulator inline and adjust the pressure to a lower rate and depending on the very load of your engine say it WOT takeoff to pulling long grades to handle the very fuel needs of your driving.  I think I would first investigate the condition of the needle and seat and ensure there is no small bits of trash or corrosion on the seat and that the float level is within specs or just a tad low for those summer conditions and the expansion rate of today's modern fuel.  Unless you running out of fuel on WOT or grades, you can do with a tad less float height.

[bluefoxamazone]

hello,

Once the car runs, it runs fine. The carb is a recently refurbished (by Mr Asche) one.

I am just worried if I install a pressure regulator to drop the pressure from the pump a little, that het mechanical pump (airtex) will not have enough force to draw through regulator and electrical pump. I have no idea if a pressure regulator has a free pass through or not. Is it reducing pressure via a membrane or just a small hole or...?

Of course the electro pump is just meant to prime but it would be nice to have a backup in case the mechanical pump fails.

grtz

[nonstop]

What about installing the regulator after the mechanical pump? Wouldn't have to consider the draw through issue, unless you are looking for originality and want it out of sight.

[medium_jon]

20 minutes ago, nonstop said:

 

What about installing the regulator after the mechanical pump?

 

That would be my suggestion 

 

[classiccarjack]

5 hours ago, nonstop said:

What about installing the regulator after the mechanical pump? Wouldn't have to consider the draw through issue, unless you are looking for originality and want it out of sight.

That has worked great for me in the past.  I put it up where I could get to it easily to allow me to adjust the regulator, if needed.

[bluefoxamazone]

off course.... this is worth trying.... I'll do that. good hint, thanks guys!

[Dave72dt]

The pressure ratings for most electric fuel pumps designed for carbs are generally in the range you mentioned, regardless of brand.  Airtex also makes a low pressure electric pump rated about 3 lbs but you may have to ask for it.  It's out there and readily available.

[1949 Wraith]

Any recommendations for low pressure fuel regulators? Are they bypass style with the need for a return line?

[Dave72dt]

Mr Gasket makes one, available at parts houses, Summit, Jegs, also.  Restrictor type, no return line required.  Quality of the unit is unknown to me personally, have sold some over the counter, prefer to sell the low pressure pump instead.

[1949 Wraith]

2 hours ago, Dave72dt said:

Mr Gasket makes one, available at parts houses, Summit, Jegs, also.  Restrictor type, no return line required.  Quality of the unit is unknown to me personally, have sold some over the counter, prefer to sell the low pressure pump instead.

Thanks

[Dartgame]

Holley makes one too, which appears more robust than the Mr gasket type, but also more expensive.