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Fuel pump or bad wiring? by saving_rossi
Started on: 06-14-2025 11:33 AM
Replies: 3 (37 views)
Last post by: Mike in Sydney on 06-15-2025 05:01 AM
saving_rossi
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Report this Post06-14-2025 11:33 AM Click Here to See the Profile for saving_rossiSend a Private Message to saving_rossiEdit/Delete MessageReply w/QuoteDirect Link to This Post
I’m nearing the end of my LG8/F23 swap. The pump was priming and it was cranking but not getting spark—now it’s getting spark but the fuel pump isn’t even priming. the tan/white wire gets 8 volts when the key is in the on position. The pink wire gets 0V but is continuous throughout the circuit (I have just been checking continuity as I go to check for breaks), and the black wire I assume is a ground, but I don’t know how to check for a faulty ground. And I haven’t messed with grounds recently.

I tried unplugging the connector and giving tan/white 12V, and it still didn’t prime. This pump is a couple months old but it has been sitting for most of those months.

How can I know for sure that this is a pump issue and not a wiring issue?

Thanks
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Mike in Sydney
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Report this Post06-14-2025 04:37 PM Click Here to See the Profile for Mike in SydneySend a Private Message to Mike in SydneyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Make sure the battery is good. You shout be seeing close tom12 volts at the connector. Next, check the fuel pump relay. If it is okay, replace the pump.

Injustice replaced the pump on my car. Same symptoms. If you replace the pump, change out all of the hoses and fuel filter while you’re there.
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saving_rossi
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Report this Post06-14-2025 10:07 PM Click Here to See the Profile for saving_rossiSend a Private Message to saving_rossiEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Mike in Sydney:

Make sure the battery is good. You shout be seeing close tom12 volts at the connector. Next, check the fuel pump relay. If it is okay, replace the pump.

Injustice replaced the pump on my car. Same symptoms. If you replace the pump, change out all of the hoses and fuel filter while you’re there.


Hoses and filter and everything are all brand new. Battery is solid. Which pin should I be seeing 12 V from? I know there’s a voltage drop due to the length of the circuit, I only saw 8.5 ish volts. From the tan/white wire.
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Mike in Sydney
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Report this Post06-15-2025 05:01 AM Click Here to See the Profile for Mike in SydneySend a Private Message to Mike in SydneyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by saving_rossi:


Hoses and filter and everything are all brand new. Battery is solid. Which pin should I be seeing 12 V from? I know there’s a voltage drop due to the length of the circuit, I only saw 8.5 ish volts. From the tan/white wire.


You should see at least 11.5 volts between the tan/white wire and the black wire. If you don’t then there is a strong possibility that you have a bad ground somewhere or the battery is bad.

Check your battery if it’s more than a year old. A battery can show 12 volts at the terminals but still be bad or on the way out. Check the voltage while cranking. If you don’t see at least 10.5 volts while cranking, consider replacing it.
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