Trip meter / odometer keeps on rolling

Hey I’ve got a good one for you guys.

I have an '89 240sx S13. Ever since I rewired my fuel pump, my odometer keeps on rolling, even when I’m not in gear and sitting still. It’s somehow linked to the RPM gauge (faster the idle, faster the odometer rolls) and it won’t stop. I’ve done a lot of looking and haven’t been able to find any info. It’s not a huge deal but if anybody can suggest some ideas for fixing this I’d appreciate it.

Thanks