Just to be clear, this started after you replaced the pump or did you replace the pump to address this?
If this was after the pump replacement, then I suspect we have an issue with the replacement pump.
However, if this was the issue prior to it then the way this works is the PCM tells the gauge what the fuel level is. So, we should check and find out what the PCM is telling it to find out if this is a gauge issue. Basically, if the voltage is fluctuating then the gauge is just displaying what it is told.
https://www.2carpros.com/articles/how-to-check-wiring
If it is remaining constant, then the gauge is the issue.
I am attaching the wiring info below so let's start with this and go from there.
Thanks
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Monday, April 4th, 2022 AT 8:49 AM