Electric fuel pump with a mechanical one problems

[V12Bill]

I have an electric fuel pump on my Lincoln , but I only use it in the event of vapor lock. If the car sits and needs fuel in the bowl, it also needs oil on the bearings. Crank it until you get gas to the carb and you will also get oil to the bearings. What is more important, getting a quick start or getting oil on the dry bearings.?

[Wltr_Mitty]

My observations on plumbing a check-valve...

When I installed my Airtex I ran out to Grainger and picked up one of these suggested check valves. A simple suck & blow test through the valve vs. the Airtex made it pretty obvious that the check valve has much greater resistance; i.e., if you have one of these check valves in parallel with the Airtex, it's not doing a thing because the Airtex path flows easier. If you have a Carter or similar pulse style pump then the valve starts to make sense because you can't pull gas through that style pump (all the time). Problem is with the extra drag placed on the fuel line from the valve, the stock fuel pump fails more frequently, so you end up getting dependent on the electric pump for everyday use anyway.

I use my electric with an on/off switch for a backup but it's also wired through a 6v relay off the ignition circuit. This way if I forget that it's switched on it shuts off along with the engine. The current load is also taken off the stock ignition switch. If I were to wire the electric full time, I would definitely want it wired through a pressure switch for safety, but for now anyway, I prefer the stealthy all original look under the hood.

[TomT/Williamsburg]

Originally Posted by Hamtown Al

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.

Al,

The Airtex pump I was using on the roadster initially, and it was isntalled over the rear crossmember with gas coming in directly from the tank and then exit to the mechanical pump, would not allow me to pull gas through it via the mechanical pump - I'll check the number vs yours.

If I shut the pump off, the car would run until I used up the gas in the bowls and then it would die.

Presently I have a check valve coming in and I'll try that using the by-pass system like Old Henry. If that does not work I will revert to the aircraft pump recco'd by Richard in FL and put it in-line.

[jdl]

Originally Posted by Step-down

JDI- E- Bay

AIRTEX E8902 6 VOLT FUEL PUMP 2.5-4psi LOW PRESSURE FUEL PUMP OR PRIMER PUMP

Thanks, our local Carquest can get the E8902 overnight.
jdl

[Old Henry]

Originally Posted by TomT/Williamsburg

I'll try that using the by-pass system like Old Henry.

Once again. The picture I posted of a bypass system is 41Fordor's, not mine. Mine needs no bypass because the Airtex 8902 flows through fine.

[TomT/Williamsburg]

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Well, I was finally able to get back on my roadster startup after Fall Carlisle.

I tried the check valve in my setup but it did not work. So, I replaced my pump with the Airtex 8902 using an in-line setup. The engine starts and fires OK with the pump on but dies with the pump off once the fuel in the carbs is finished. Charlie NY redid the pump.

I will now try it by bypassing the electric fule pump all together, and just be mechanical. I will also check the mech fuel pump rod to see if it's properly seated in the cup of the pump arm.

Any other ideas? I did notice the electric pump dioes have to run pretty strong when I first turn the switch on to start, regardless of whether the car had been running the mechanical or electric fuel pump.

BTW, can a fuel filter thwart the mechanical pump?

[bbrocksr]

Originally Posted by TomT/Williamsburg

Well, I was finally able to get back on my roadster startup after Fall Carlisle.

I tried the check valve in my setup but it did not work. So, I replaced my pump with the Airtex 8902 using an in-line setup. The engine starts and fires OK with the pump on but dies with the pump off once the fuel in the carbs is finished. Charlie NY redid the pump.

I will now try it by bypassing the electric fule pump all together, and just be mechanical. I will also check the mech fuel pump rod to see if it's properly seated in the cup of the pump arm.

Any other ideas? I did notice the electric pump dioes have to run pretty strong when I first turn the switch on to start, regardless of whether the car had been running the mechanical or electric fuel pump.

BTW, can a fuel filter thwart the mechanical pump?

Yes, You shouldn't put a filter on the suction side.
Bill

[hardtimes]

Originally Posted by TomT/Williamsburg

Well, I was finally able to get back on my roadster startup after Fall Carlisle.

I tried the check valve in my setup but it did not work. So, I replaced my pump with the Airtex 8902 using an in-line setup. The engine starts and fires OK with the pump on but dies with the pump off once the fuel in the carbs is finished. Charlie NY redid the pump.

I will now try it by bypassing the electric fule pump all together, and just be mechanical. I will also check the mech fuel pump rod to see if it's properly seated in the cup of the pump arm.

Any other ideas? I did notice the electric pump dioes have to run pretty strong when I first turn the switch on to start, regardless of whether the car had been running the mechanical or electric fuel pump.

BTW, can a fuel filter thwart the mechanical pump?

Hey Tom,
THANKS , for your followup/input! Coincidently...I'm in your exact situation right now! See the pic of my porboy duel/parallel fuel line setup below. I worked off of 41fordor picture/idea which was posted here also.
The pictured elect pump is a CARTER #P60504.
I am having exact same situation that you've stated. My 'TEE' connectors are: straight thru for elect pump and mechanical line is off the T.
51merc shows diag of the other T hookup. Since my pump is on the STRAIGHT THRU line, I reasoned that that line would work...as I was told that this CARTER model only allows fuel one way. If true(one way) I shouldn't need a one way valve..no
BTW- my mechanical pump works GREAT with this setup. But, NO fuel from elect pump...with fuel line disconnected at mechanical pump??
I installed this carter after reading in archives that is was recommended.

Can you see what I'm missing in this situation to get fuel from elect pump with my setup?

[Old Henry]

Originally Posted by hardtimes

Can you see what I'm missing in this situation to get fuel from elect pump with my setup?

You'd still need a check valve in the bypass hose or the pump would just pump in a circle as has been explained before and illustrated in 51MERC-CT's #5.

[hardtimes]

Originally Posted by Old Henry

You'd still need a check valve in the bypass hose or the pump would just pump in a circle as has been explained before and illustrated in 51MERC-CT's #5.

Hey Old Henry,
Ok then...I'll put that check valve in and let you all know what the results are...thanks for helping.

[hardtimes]

Originally Posted by Roger/Sacramento

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?

Hey Roger,
Yes that works great for 'priming' the fuel line and just takes a few seconds ! Just remember to disconnect the fuel line at the mechanical pump first...TO ALLOW the air to be pumped out as the fuel fills the lines.
BTW put the disconnected gas line into a container to catch what comes out till you get back up there,eh. 'What' comes out is also crud/anythingforeign in line

[40cpe]

Originally Posted by TomT/Williamsburg

Al,

it was isntalled over the rear crossmember with gas coming in directly from the tank

I might be all wet here, but with the pump on the top of the crossmember, is it below the tank? Electric pumps need to be below and near the tank.

[Rand]

This is what I did that I learned over at shoeboxford.com and works great for me. Just use for start ups with a toggle switch that you have to hold in the on possision to keep from leaving it on. Have that part number somewhere, also using a 6volt pump that the mechanical pump pull through just fine, got it from Chris at Shoeboxford.com ..just be sure and mount it as near to the tank as you can ..Randy