Weird fuel gauge question

[starfish]

My truck was sitting around for years and I finally got it up and running.I did put a new FP in the tank(1987 Blazer TBI 5.7).I also made sure all the wires were ok on the FP assembly.I also checked the float to make sure it was working properly.The problem is that my fuel gauge was on a 1/4 tank while my truck was idling and all of a sudden it when past the full mark and staid there!Anybody ever seen this happen before?I know my tank is only 1/4 full.

 

[ktmoutfront]

Could be a grounded lead from the sender on the pump.

 

[starfish]

The only wire I see grounded is the wire on the outside of the assembly.I just grounded it to the frame.The other to wires coming out, plug to the harness

 

[ktmoutfront]

The wire going from the sending unit to the gauge. May be rubbed through or pinched. Or the sending unit is toast. Mine have always gone to empty though.

 

[starfish]

Ill check it out again tomorrow.Thanks