Testing for faulty fuel pump

[Beerhunter]

Hello all, I had searched this before but for whatever reason I cannot find the tread again.

Basically, I am trying to detirmine if my fuel pump is toast. I don't hear whirr for 3 seconds when I turn the key. I'm thinking that all I have to do is put a multimeter on the connections at the fuel pump. If it reads ~12 volts for 3 seconds then the fuel pump is shot.

My question is this... if I don't show any voltage then what else can it be assuming that the relay and fuses are fine? Is there anything else that would prevent the fuel pump from starting up?

 

[JeremyH]

Inertia cutoff switch is another piece to the puzzle.

But yes if you have 12 volts to the top of the fuel hat at key on but no fuel then its the pump most likely.

 

[Beerhunter]

Inertia cutoff switch is another piece to the puzzle.

Oh ya, of course. Checked it and it was fine.


unless it is a failed Inertia Switch... hmmm

 

[JeremyH]

If you have voltage going to it but not from towards the pump.

But just check at the fuel hat plug first with the key on.

 

[Beerhunter]

If you have voltage going to it but not from towards the pump.

Bu just check at the fuel hat plug first with the key on.

Ya, that is the easiest thing to test for. I have never changed out a fuel pump so I wanted to be sure that I wasn't missing something. Honestly my fingers are crossed that I will find voltage!

Thanks Jeremy

 

[Beerhunter]

Ok, it seems to be confirmed that it is a fuel pump (...maybe). Cost is around $100 at the rip off parts store. When I plugged the volt meter in I measured 00.02 and when I turned the key on it went to 11.28. I plugged it back in to the pump and I could not hear it turn on. One question though...
I'm just thinking of this now but, I have been getting this DTE FLI error from time to time (about every 2 months). I haven't really worried about it too much as it return to normal after a few minutes. I have now read that this may be due to a faulty Fuel Sender Card. So.... my questions are,

1) would a failed Fuel Sender Card prevent the fuel pump from starting up with the key turned on?

2) why would my multi-meter not turn off after 3 seconds when reading the voltage being sent to the fuel pump? Does it keep sending voltage until the fuel rails sense fuel?

 

[JeremyH]

Ok, it seems to be confirmed that it is a fuel pump (...maybe). Cost is around $100 at the rip off parts store. When I plugged the volt meter in I measured 00.02 and when I turned the key on it went to 11.28. I plugged it back in to the pump and I could not hear it turn on. One question though...
I'm just thinking of this now but, I have been getting this DTE FLI error from time to time (about every 2 months). I haven't really worried about it too much as it return to normal after a few minutes. I have now read that this may be due to a faulty Fuel Sender Card. So.... my questions are,

1) would a failed Fuel Sender Card prevent the fuel pump from starting up with the key turned on?

2) why would my multi-meter not turn off after 3 seconds when reading the voltage being sent to the fuel pump? Does it keep sending voltage until the fuel rails sense fuel?

1) No

2) Correct at key on the pcm sends full voltage to the hat to prime the sytem and establish pressure so the voltage stays and no pump no worky.

The DTI FLI thing may be a dirty level sender.

http://www.s197forum.com/forum/showthread.php?t=24405

 

[Beerhunter]

1) No

2) Correct at key on the pcm sends full voltage to the hat to prime the sytem and establish pressure so the voltage stays and no pump no worky.

What year is your car?

2005 GT Premium Convertible

 

[Mustang30212]

You can usually pickup a used fuel hat on here pretty cheap...that is unless Jeremy beats you to it...LOL.

Or you could go ahead and buy and upgraded pump setup from him for future mods.

RH

 

[Beerhunter]

Does anyone know if these Airtex fuel pumps are any good. I've only heard of Carter before but they are a bit more expensive.

http://www.amazon.com/Airtex-E2457M...:ford:mustang&keywords=2005+mustang+fuel+pump

 

[JeremyH]

Did you get my pm?

 

[Beerhunter]

Did you get my pm?

Somehow I missed it. I just replied. Cheers!

 

[JeremyH]

Somehow I missed it. I just replied. Cheers!

Replied back, got it here ready for ya.

 

[wayne613]

So his issue is solved, so hopefully this isn't hijacking...
My own fuel pump is weak(I believe - issues starting recently waiting for it to prime). I would like to future proof the pump and/or fpdm, so I was unable to find specs on the GT500 dual one for LPH, will this equate to near the same or possibly beyond Jeremy?

 

[JeremyH]

Not sure what your asking exactly?

 

[wayne613]

Not sure what your asking exactly?

Sorry, I think I might have mixed a few threads together when searching and just responded in this one, instead of the one you mentioned the pumps you sell. I saw in addition to this thread your re-furb thread that you sell the upgraded pumps in. I'm trying to find out if going that route is the same or better than going a dual pump route (FRPP/Saleen/etc) is all.

My bad.

 

[JeremyH]

He had a bad stock pump and replaced it with a newer stock pump.

 

[05stroker]

So, what should the voltage read on the pumps if they are working?

I have three, two pumps that run all the time and a third that comes on at 10 psi, If I have two running at key on I will still see pressure at the rail but could still have a bad pump. In this scenario, how would you test the voltage on both pumps to see if they are both working or not?

 

[JeremyH]

Not sure I follow your question Billy. Your return setup will send full voltage to the pumps at key on wether they are working or not.

If you suspect a bad pump remove power from one pump at a time and see if you still get pressure.

 

[05stroker]

Not sure I follow your question Billy. Your return setup will send full voltage to the pumps at key on wether they are working or not.

If you suspect a bad pump remove power from one pump at a time and see if you still get pressure.

Is there a way to test resistance in the circuit to see if there is any variance between the pumps?

Didnt read the second part, I will try that.