Electric fuel pump with a mechanical one problems

TomT/Williamsburg

TomT/Williamsburg

Well-known member
I wanted to do the same thing which is setup in my coupe, flip on the mechanical pump first after the car has been sitting for a few days, start it, then flip off the electric pump. But, I'm using a cheap pump and wanted to get a better one that I can depend on if my mechanical pump dies.

My idea - I have both pumps installed - from the tank I have a T fitting, one line goes around the electric pump, the other to the pump, there's another T fitting on the other side of hte pump where the line exiting the pump and the line that did not go to the pump come together.

My pproblem - I can't get gas through the engine mechanical pump with the electric pump running. I pinched off the by-pass line from the tank and I got fuel to the fuel bowl of the engine mech pump but nothing comes out of the mechanical pump up to the carbs as I turn the engine over whether the electric pump is running or not.

I think it's the nature of the electric pump I'm using - my coupe has a cheapo electric pump from Advance "in-line" out of the gas tank and both the flattie and electric pump operate normally/as descibed above. The cheapo pump is electronic or pulse operated while the pump I'm using on my roadster is somethng different - kind of like a whine?

Anyway, I'm going to get rid of the T-fitting setup and use a cheapo pump, setting it up likes it is in my coupe - I'll keep you posted.

Any ideas why the pump I'm using would not work?
 
I have a cylindrical electric fuel pump(AC) and a Speedway mechanical pump on my flathead.I use the elec to fill the bowls when the car has been sitting for over a week without starting.I then turn the elec pump off and start the car normally.Never had a problem so far.
 
Like Deuce Lover, I use the electric inline pump momentarily to prime the mechanical pump. No problems at all. I am using the Airtex E8902 6volt, low pressure pump. Works great! Pat
 
FWIW, I use the stock mechanical pump in conjunction with a 6v Airtex E-8011 electric pump on a single fuel line. The Airtex is used mainly for priming, but has been handy as a backup several times when the mechanical pump had problems. The Airtex allows the mechanical pump to pull through freely when not in use. Believe the 12v version of the Airtex pump is E-8012.
 
Tom,
If you decide at some point to upgrade your electric pump I strongly
recommend the POSI-FLO pump. It is electronic, and has a composite body. On
2x2 installations I use their 4 to 7 psi pump with no regulator required. With 2 2's
the pump delivers a steady 3 psi with no issues. I purchase these little dudes at
Carquest....#41-510. POSI-FLO also makes a lower pressure pump #41-509.
Charlie ny
 
TomT/Williamsburg said:
I wanted to do the same thing which is setup in my coupe, flip on the mechanical pump first after the car has been sitting for a few days, start it, then flip off the electric pump. But, I'm using a cheap pump and wanted to get a better one that I can depend on if my mechanical pump dies.

My idea - I have both pumps installed - from the tank I have a T fitting, one line goes around the electric pump, the other to the pump, there's another T fitting on the other side of hte pump where the line exiting the pump and the line that did not go to the pump come together.

My pproblem - I can't get gas through the engine mechanical pump with the electric pump running. I pinched off the by-pass line from the tank and I got fuel to the fuel bowl of the engine mech pump but nothing comes out of the mechanical pump up to the carbs as I turn the engine over whether the electric pump is running or not.

I think it's the nature of the electric pump I'm using - my coupe has a cheapo electric pump from Advance "in-line" out of the gas tank and both the flattie and electric pump operate normally/as descibed above. The cheapo pump is electronic or pulse operated while the pump I'm using on my roadster is somethng different - kind of like a whine?

Anyway, I'm going to get rid of the T-fitting setup and use a cheapo pump, setting it up likes it is in my coupe - I'll keep you posted.

Any ideas why the pump I'm using would not work?
Click to expand...
If this is what you are describing, the pump is just pumping in circles.
 

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Thanks fellas - yes, my idea is to prime the carbs first to avoid excessive cranking. I'm going back to the tried and true method of being inline.

51 Merc, I think you are right about that. Now my car is going in circles just like me - LOL!

I'll check into the Carquest unit, Charlie ... I need 12 volt unit ....

Thanks again everyone! The Fordbarn at its best ....
 
Your simplest fix is to leave everything just like it is but add a check valve in your line that bypasses the electric pump to allow fuel to only go toward the engine. That way when the electric pump is pumping it will keep the fuel from just recirculating back around but allow the mechanical pump to pump the fuel past the electric pump when it's not on. See 41Fordor's #4 on this thread: http://www.fordbarn.com/forum/showthread.php?t=81408

Here's his picture that illustrates his installation:

2012-06-24_09-21-33_195.jpg
 
TomT/Williamsburg said:
Any ideas why the pump I'm using would not work?
Click to expand...
Some electric pumps will feed through when not running, others will not. I went through the same selection process, and I can recommend from experience what I'm using.

This is a Facet 40106 recommended for experimental aircraft use. I bought it from Aircraft Spruce & Specialty for about $33,

http://www.aircraftspruce.com/catalog/eppages/facetpumps.php

Even with my fairly hairy 276's 500 cfm four-barrel, the stock mechanical pump has no trouble at all pulling enough fuel from the tank for high-speed highway driving.

Mine's 12 volts, but I think Facet also make 6-volt versions.
 

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I will be starting my engine up soon and have a mechanical pump only. A friend told me to put a rag around an air hose and stick it in the tank fill opening. That will push the gas to the pump and eliminate unnecessary cranking. Any thoughts there?
 
Yes this will work. I recently helped a friend drain a half tank of gas that had been in this 74 Chrysler for years. We disconnected the gas line at the fuel pump and all the gas was forced out. Now that I think about it, it may not work with the gas line still connected.??
 
Old Henry - a picture IS worth a 1000 words. I'm basically set up the exact same way, just more over the rear crossmember. I'm also 12 volts, Richard and thank you for the pump suggestion - I just ordered one and a check valve so, we'll see where that leads me.

Thanks again, gents - great info here ....
 
Old Henry said:
Your simplest fix is to leave everything just like it is but add a check valve in your line that bypasses the electric pump to allow fuel to only go toward the engine. That way when the electric pump is pumping it will keep the fuel from just recirculating back around but allow the mechanical pump to pump the fuel past the electric pump when it's not on. See 41Fordor's #4 on this thread: http://www.fordbarn.com/forum/showthread.php?t=81408

Here's his picture that illustrates his installation:

2012-06-24_09-21-33_195.jpg
Click to expand...
Old Henry is on the mark with his setup. Went crazy for a couple of weeks installing the Carter P-60430 pump inline with my machanical pump and almost got run over by a dump truck when trying to go up a hill. Called Carter and the tech told me with this gear pump the cars machanical pump can't pull enough fuel thru it so you need to install a bypass check value in parallel with the electric pump. Have the same setup in my 41 Lincoln. Now works great and now make it over all the hills. Happy V8ing! Larry
 
Tom - a check valve set, up as mentioned previously, is absolutely necessary to make your system work right. Lots of good info - and pix - here. Good luck!
 
I use the 12v version of the Airtex pump (E-8012) that I get from AutoZone on a number of my cars. Stock mech pumps have pulled gas thru them without incident over the years on a number and variety of old Fords. Put the pump near the tank.
 
Larry in NH said:
Old Henry is on the mark with his setup.
Click to expand...

That is not my set up. I was just showing 41Fordor's solution to the Carter pump. I use the Airtex that the mechanical pump can pull through. Much simpler installation. No need for bypass line with check valve.

Fuelpumpelectric.jpg
 
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