Fuel pump diagnosis?

[fwi]

I was just tooling along today and a block from my house the car just stopped, turned out the Holley blue pump just quit. It's been on there for many years .....I did check all the wiring, the fuse, etc...those are ok. Of course there is nothing when I turn the fuel pump on.
How do I confirm it is in fact the fuel pump?

 

[SlinktRR]

it is a Holley electric pump, that is how you know. They are known to fail without warning. You can test continuity and voltage at the pump, check ground. Other than that, dead pump.

 

[1967coronet]

unwrap that black electric tape and check that connection.

 

[Bigal75]

Put power directly to the pump. That will tell you.

 

[fwi]

Hot wired it, runs fine........now the mysterious electrical gremlins! I' ll check the ground wire next.

 

[Bigal75]

Is the the pump wired to a relay? If so that may be the issue.

 

[fwi]

What is the square box on the right?

 

[Bigal75]

Not sure that that is.

 

[Bigal75]

Looks like another fuel pump

 

[fwi]

Well it does have 2 speeds on the fuel pump switch at the dash, one position gives me about 5 psi, the other about 9.
I have never heard of a 2 speed fuel pump so maybe this solves the mystery and maybe the culprit.

 

[Bigal75]

You should run your pump at the max setting ( full voltage) and then regulate the fuel pressure. Maybe that small pump died causing your issues.

 

[fwi]

Doesn't work on either hi or low at the dash, but both fuel pumps work when hot wired, so.......it must be in the wiring somewhere?
Relay perhaps....if there is one where oh where can it be!

 

[Bigal75]

Look under the dash lol.

 

[fwi]

Look under the dash lol.

Yes I am trying to hire a midget to get down and around the roll bars for me....

BTW, thanks for your help.

 

[Bigal75]

Lol. Sometimes it easier just to pull out the seat. Not much you can do about roll bars. Good luck and my pleasure.

 

[hangn0ut]

Do yourself a favor and drop that plate on the bottom of the pump. There is a long,thin inlet screen that needs cleaning. You should probably take the pump out and flip it over to take it apart cause the rotor and vanes can drop out. Very easy and you will find crap in it.

 

[moper]

Get a test light and trace the wires. Pretty easy to diagnose. When you find either the wire, or the component that has power in, but not out - that's your problem.

 

[fwi]

Both pumps ran fine when I hot wired them. Each pump has one ground (checked) and one hot wire, each of which run next to each other all the way to the dash toggle switch.
I'll have to find the power source for the switch.

 

[fwi]

Do yourself a favor and drop that plate on the bottom of the pump. There is a long,thin inlet screen that needs cleaning. You should probably take the pump out and flip it over to take it apart cause the rotor and vanes can drop out. Very easy and you will find crap in it.

I will do that too.

 

[SlinktRR]

I'm glad I was wrong. Rewire using a new toggle switch and a relay for main power, don't see much use in the multiple setting switch. Relays can fail, the switch may be bad as well. My fuel pump switch is next to the fuse box in the glove compartment.