6v electric fuel pump: help needed

[Worden18]

My brother and I spent the day installing a 6 volt electric fuel pump in my 48 B1C.  I got the pump from DCM.  It does not need a regulator.  It is installed correctly back near the fuel tank with a fuel filter between the tank and the pump, and another fuel filter up near the carburetor. I completely bypassed the mechanical fuel pump.  I put a metal plate over where the mechanical fuel pump used to be.  Everything is wired correctly and the pump sounds nice when we turn the key on. For the life of me we cannot figure out why we cannot get gas up to the carburetor. The truck ran fine before the mechanical fuel pump failed. And the truck starts right up when we dump gas down the car with a little cup. but the new pump for some reason is not getting fuel up to the carburetor, not even close I don't believe. And we have left the key on for minutes at a time to make sure that it would pull the fuel up, and there is nothing there. and yes, there is plenty of gasoline in the tank. What are we doing wrong? Is there a way to prime the pump? What have you guys done? ?

Edited May 16, 2021 by Worden18

[Tooljunkie]

Blow in the tank. Double check the fuel line for kinks. 
Possible fuel pump is faulty, or wired backwards. Im betting wired or plumbed backwards. 

[Worden18]

6 minutes ago, Tooljunkie said:

Blow in the tank. Double check the fuel line for kinks. 
Possible fuel pump is faulty, or wired backwards. Im betting wired or plumbed backwards. 

I know for certain we have no kinks. We've checked and double checked that it's very straightforward.  I guess it's possible the pump is faulty although it sure does sound nice. as far as it being wired backwards, now I am very unsure about that.  The black wire should be the ground, and the red wire should be the hot wire which is run up to the ignition switch. My gosh do we have it backwards because my truck is a 6 volt positive ground?

Edited May 16, 2021 by Worden18

[Jerry Roberts]

You could check the pump by putting the inlet in a gas can .  Is your fuel ling plugged going into the tank ?

[Worden18]

22 minutes ago, Jerry Roberts said:

You could check the pump by putting the inlet in a gas can .  Is your fuel ling plugged going into the tank ?

Thanks for this advice.  The fuel line isn't plugged. It's a brand new tank and was running perfectly before the mechanical pump gave out. And it was spraying gas all over the place when the last thing we did was hook up the fuel filter right at the gas tank before the fuel pump.  I'll certainly try the inlet in a gas can. 

Edited May 16, 2021 by Worden18

[Young Ed]

Did you try cracking the line along the way to see if fuel was making it to any points? 

[maok]

5 hours ago, Worden18 said:

I know for certain we have no kinks. We've checked and double checked that it's very straightforward.  I guess it's possible the pump is faulty although it sure does sound nice. as far as it being wired backwards, now I am very unsure about that.  The black wire should be the ground, and the red wire should be the hot wire which is run up to the ignition switch. My gosh do we have it backwards because my truck is a 6 volt positive ground?

If you are positive ground then the red wire of the pump should be grounded and the other to your live wire from the ignition switch.

[maok]

Also, mount the pump as low as possible.

[Worden18]

Thanks for all the responses fellas. I think we have it wired backwards.  I will report back later today.

[Plymouthy Adams]

do ensure if you are positive ground that the pump's ground wire circuit is floating....if shared with the pump body....you must fully isolate the pump from body when mounting...electric pump should be set on isolation mounts as it is to begin with...else it will be a bit noisy.

[bkahler]

I had a similar problem years ago on a race car.  The problem ended up being a very slight leak on the suction side of the pump.  All it was doing was sucking air.  Tightened the fitting and problem solved.  

[Merle Coggins]

If it’s a “clicker” type pump I don’t believe they are polarity sensitive, but wouldn’t hurt to reverse the wires to test it. Also, it may seem like an insensitive question, but are you sure you have the inlet and outlet plumbed in the correct direction? If it’s being fed gas via gravity feed, and it’s clicking away with the key on, it should be pumping. 

As Ed said, crack a line loose on the pressure side to purge the air and check for fuel. 

[Worden18]

May 16:

Okay everyone, thanks for all of the responses and tips. Always greatly appreciated because I'm not very good at this stuff.

 

The problem was the wires were switched. It was that simple.  After we cut and respliced everything the truck started right up.  spent the day messing around hooking up another brake and tail light as well.  We've also taken several short shakedown cruises to keep an eye on leaks engine temperature oil pressure etc. So far so good!

[Tooljunkie]

Well, isnt it a great feeling when the problem is conquered? That is  a good looking old beast. You will get lots of thumbs up im sure. Enjoy putting around, i sure do. 
my wife gets a real kick out of cruising and all the attention we get.