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Fuel pump out again. I'm losing it.

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Old 07-02-2016, 11:46 AM
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Those voltages at the resistor art spot on. Other types of electric motors will burn up under powered. That DC motor is different I think, (apples and oranges), but still you could check that that 9.5 is getting to the pump OK. Guess you know the ground is good?

Yer welcome. Amperage is the rate the water is flowing into the bucket. Voltage is the pressure in the hose.
Old 07-02-2016, 11:57 AM
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How many volts do you have at the pump?
Old 07-02-2016, 12:08 PM
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Originally Posted by cruiser54
How many volts do you have at the pump?
At the pump with it running, at idle, with ballast resistor hooked up at have 8.9 volts.

At pump with with it running, at idle, with ballast resistor unhooked I have 13.1 volts.

Does the fact the ballast resistor has spot on voltage at the resistor mean that the problem is after the BR in the circuit? Just a guess.
Old 07-02-2016, 12:10 PM
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Originally Posted by DFlintstone
Those voltages at the resistor art spot on. Other types of electric motors will burn up under powered. That DC motor is different I think, (apples and oranges), but still you could check that that 9.5 is getting to the pump OK. Guess you know the ground is good?

Yer welcome. Amperage is the rate the water is flowing into the bucket. Voltage is the pressure in the hose.
I'm going to recheck and re-do the new ground wire and make sure the metal is extra shiny. At the pump I was only getting 8.9 volts at idle.
Old 07-02-2016, 12:12 PM
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Originally Posted by Chick-N-Picker
At the pump with it running, at idle, with ballast resistor hooked up at have 8.9 volts.

At pump with with it running, at idle, with ballast resistor unhooked I have 13.1 volts.

Does the fact the ballast resistor has spot on voltage at the resistor mean that the problem is after the BR in the circuit? Just a guess.
You're losing some voltage in the wiring but not enough to be alarmed about.

I would leave the resistor bypassed.

Now, it's pump time.

Is it sucking air? something wrong with the installation? Tank dirty inside? Did you have a new sock on the pickup tube?
Old 07-02-2016, 12:14 PM
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Originally Posted by Chick-N-Picker
I'm going to recheck and re-do the new ground wire and make sure the metal is extra shiny. At the pump I was only getting 8.9 volts at idle.
Not a bad idea. You know you can check the ground with your meter, right?

I just thought of something. The ground wire was not tight at the pump or maybe the flange on my wife's XJ. Wire melted inside the tank....

Made a new wire and made sure the blades weren't loose like the one that burned. That was years ago.
Old 07-02-2016, 12:15 PM
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Here's the wire.
Attached Thumbnails Fuel pump out again. I'm losing it.-fp-wire.jpg  
Old 07-02-2016, 12:27 PM
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Originally Posted by cruiser54
Not a bad idea. You know you can check the ground with your meter, right?

I just thought of something. The ground wire was not tight at the pump or maybe the flange on my wife's XJ. Wire melted inside the tank....

Made a new wire and made sure the blades weren't loose like the one that burned. That was years ago.
No I did not know I could check ground with my meter. How do I do that and what number should I look for? There's only one ground correct?
The one that runs up behind the spare tire. Which I ran the new one like you said but just asking that's the only ground I need to check?
Old 07-02-2016, 12:45 PM
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Set your meter to ohms. Touch the leads together and the meter should read 0.

Now, touch one lead to a known ground like where you put your new one and rouch the ground wire at the fuel pump harness with it unplugged. Should read close to 0.
Old 07-02-2016, 12:46 PM
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Originally Posted by cruiser54
You're losing some voltage in the wiring but not enough to be alarmed about.

I would leave the resistor bypassed.

Now, it's pump time.

Is it sucking air? something wrong with the installation? Tank dirty inside? Did you have a new sock on the pickup tube?
I don't know if it's suckling air or how to know that.
Instead of trying to ask you a million question which I could do, I'll tell you what I've done everytime.

I went to NAPA and got a new fuel pump assembly everytime.
I then install it which is fairly easy.
What sock and would the new assembly not have it on it?

As far as trash in the tank. That is a possibility but I thought since it went out at practicaly exactly the same mileage everytime that it was a constant such as voltage or ground wire. If it was sucking trash wouldn't it go out after varying times as it sucked enough trash?

I've got until Tuesday so I'm dropping the tank this time and cleaning it anyway.
Old 07-02-2016, 12:51 PM
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Before pulling the tank, just shine a light in there.

Inspect the module to see if the ground wire is tight at the terminals on each end.

Don't get too hung up on the "time" thing. Airtex pumps are absolute crap.

at the bottom of the assembly where the fuel is sucked up is a kind of flat sock/screen.
Old 07-02-2016, 12:53 PM
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Originally Posted by Chick-N-Picker
What sock and would the new assembly not have it on it?
Maybe we are on to something here. I'm not sure a new assembly comes with the filter screen. (which is easy to knock off while removing the pump).

Has there been a filter screen on the pumps you have been installing? (you may find some number of them in the tank)
Old 07-02-2016, 12:58 PM
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Originally Posted by cruiser54
Before pulling the tank, just shine a light in there.

Inspect the module to see if the ground wire is tight at the terminals on each end.

Don't get too hung up on the "time" thing. Airtex pumps are absolute crap.

at the bottom of the assembly where the fuel is sucked up is a kind of flat sock/screen.
Its white correct. You mean what I call the strainer. Yes it is on there.
Good call on shining a light. I can tell you've been there and done that. I would have dropped it first haha.

I'm thinking of just going to NAPA Tuesday and getting a refund, if they'll give it, then going to JY to get stock sender and order me a Bosch pump.

First however I want to find the issue or rule out everything else.
Old 07-02-2016, 01:03 PM
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where are you located?
Old 07-02-2016, 01:08 PM
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Originally Posted by cruiser54
where are you located?
Boiling Springs, NC.


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