1991 New Fuel pump... gauge floats now

Okay .. about a year ago I had my XJ towed to the dealer because the fuel pressure regulator sprang a major leak. The dealer installed a new o-ring on the injector rail and said it was due to the original fuel pump not pressurizing...

So they installed a new fuel pump... it cost me an arm and a leg.

Well, everything works fine except now my fuel gauge bounces around. When I fill the tank the gauge shows full when I'm stopped, then after I take off the needle moves down to the 7/8 mark, then moves back to full when I stop again.

The needle does this until the tank is closer to empty then appears to stabilize and move slowly down as the XJ consumes the fuel.

Before I had them install this OE fuel pump my XJ never did this...

Was the pump installed correctly?

Joe, need your infinite wisdom here...

.

Ok, maybe the dealer tech didn't get the rubber snubber on the end of the fuel pump assembly locked into the tank properly and that could allow things to move a bit under acceleration/deceleration. I guess I would pull the pump out and take a look at the assembly, see if you can get it seated better.

You will want the tank a little down on fuel.

Good luck.