Fuel Gauge issue

[mrspeedy69]

I put a new fore fuel system in the car and my gauge showed no fuel at all. Took the tank back out and found out I had messed up the sending unit. Bought a new one put it in and all worked.

While data logging and tuning the car I noticed the gauge would read fine when the key was first turned on. Then after a while, sometimes a few minutes to several minutes and the gauge would read empty and low fuel would come on. I've had a few times that it does the opposite and reads full when it's not. It did throw a cel P0463 as well.

Could it be a bad sending unit even though it's new? Or something else? The only other thing I've wired up was a boost gauge. I was going to unhook it and see if that was causing some grounding issues.

 

[cj428mach]

How long does the gauge issue last? A second at a time?

Its common with sct for there to be cluster problems when datalogging.

 

[mrspeedy69]

That was my initial thought because I had things grounded and stuff to datalog. However, I unhooked everything last night and went for a test drive. About 5 minutes into the drive the gauge went to empty and never came back until I shut the car off and turned the key back on. It seems like when it does do this it doesn't come back until the car is turned off. However, I honestly haven't driven it a bunch yet.

EDIT: I haven't unhooked the battery and let the car sit since I've data logged. Do you think it would be beneficial to do this and just see?