9Dragnfly2

I have a 92 SC400, my fuel pump stays running about 10 mins. after I shut the car off. If you pull the efi fuse or relay and put it back in it shuts off. It's been doing it now for about 4 months. Bought a used Fuel Pump ECU and still does it so ended up bypassing the ECU. That didn't help at all. Swapped the relay with the defrost one and still does it. If I were to start the car to move it and shut it back off, the pump would go off immediately but if I drive to work or let it run for a few minutes the pump stays running but later shuts off. I've searched threads and seen a few other members with the same problem but no luck at all. If anyone knows any other solutions help me pleaseee!!! It's starting to make my battery weaker.

DEMONSC4

Simply from reading your post, no research what so ever. My first thought is that either your fuel pump is doing something that tells your PCM to keep power after key off. OR it is simply your PCM. But as far as power to the pump goes, the PCM is the boss. How did you bypass your fuel pump ECU?

9Dragnfly2

I stripped the green and black/red wires and soldered them together.