Fuel tank sending unit probs

[destinbeachman]

Last year I installed a new Autometer fuel gauge and was getting good readings until about a month ago.It seems as though the float is sticking.I checked the connections and grounds.So I bought a new sending unit from LMC.Anyway,I was just messing around and pulled the connection from my tank and put it on the new unit,connected the ground wire and was playing around with it to make sure the gauge would respond.It does but it doesn't sweep the entire gauge.Stops before 3/4 full.Does anyone know of a reason why the sending unit would show resistance differently out of the tank in the open air versus inside?Would the gas make the resistor doohickey act differently?I surely don't want to go to the trouble of pulling the tank and installling the sending unit if that's not where the problem is.Thanks-Allen

 

[dyeager535]

You say it acts like the float is sticking, is the gauge acting the same way with BOTH senders?

 

[destinbeachman]

Right now the gauge won't read more than half full and won't go but a bit lower than 1/8.Previously it was right on the money.With the new sending unit connected and letting the float move it reads further in both directions but still isn't right.Won't go to 3/4 full.Could be that I have a faulty gauge.I'll keep playing with it for a while longer.

 

[dyeager535]

Likely a faulty gauge if the new sender doesn't work correctly. Make sure all your connections are good, (at the gauge, sender, junctions, and wire in between) although with bad connections you *probably* wouldn't have a working gauge at all.

IIRC you've got a TINY bit of play in the rheostat that can be used to adjust the float measurement (at least on the TBI stuff) by loosening one or the other of the screws, but probably not enough to even get 1/8 tank difference.

If you've got a stock gauge still around, you can mock the setup outside of the truck, or at least alongside it.