Hi all,
I've just replaced my fuel pump with a brand new assembly. Now when I drive the gauge moves to show less gas, and when I break it goes to show more gas than I have, and when I stop it shows the normal level. Any idea what the problem is?

Thanks
AL

 

That's just fuel sloshing around in the fuel tank. When you accelerate the fuel moves to the rear of the tank away from the float which makes it ride lower and the gauge will read less fuel in the tank and when you brake the fuel moves to the front of the tank and closer to the float which makes it ride higher and reads more fuel in the tank.

 

is it normal? It didn't do that with the old pump. or any other car I've seen.. unless going up or down a steep hill

 

When you turn the key, does the fuel gauge flick straight round to the reading or does it take a second or two to climb up?

 

My 96 does it.

 

is it an after market pump?

 

I believe the pump was replaced just before I bought the Jeep in 2017.

 

When I replaced my pump and sending unit with a Spectra in my 92, it does the same thing. The gauge is reading pretty accurate (I think). It seems that it is somewhat normal with the newer units. Maybe give it some time to break in, I noticed it does not do it as much as when I first put it in.

 

It's normal for the gauge to shift a little when body roll or transfer happens. Taking a sharp corner or accelerating briskly are the two common instances that come to mind.