It worked great but when i pulled out the 307 to put in a olds 350 and it sat for about 6 months. The gas gauge has been messed up ever since. It will work for up to a week and then stop. It will also come on once in a while when i take a sharp bend. Any input would be great. Thank You

 

Well, the first suspect in a flaky gauge is a bad ground, usually at the point where the wire coming from sending unit on the tank attaches to the frame under the car. It's probably just a coincidence that it happened near to the time when you swapped engines. There's nothing about the engine itself or anything near it that has anything to do with the fuel gauge.

 

Any harness that was disconnected or handled is suspicious. There may have been a connector loosened or the gauge send wire is crushed or disturbed from the swap effort.

Retrace where you worked and messed with wire paths. I think the swap may be related to the gauge failure. You may need to shoot resistance readings point to point checking for opens or grounds.

 

Thats what i thought i checked the ground and cleaned it just to be sure but its still not workin. I am thinking about droppin the tank because some one told me the float be getting stuck up. I figure if it was it would still show a reading. It just says is all the way empty

 

Do you have juice at the tank? Try running a hot wire from the battery directly to the tank hot wire if the gage works look for a short or bad connection... Tedd

 

Well do thank you ted

 

Wait! You should never have Battery Power at the tank sender side. The power is applied at the dash side to the gauge. The gas-tank sender reads variable resistance as the float moves to ground. Two wires go to it. A local ground to one side and the gauge send wire to the other side. No sparks can be near a grounded tank - think about it.

 

So let me jump in and get a clear understanding because my gauge doesnt work either but I have no wires going to the front of my car. There are three total wires.

1. A Power wire going to the gauge.
2. A ground wire going from the sending unit to the frame.
3. Another ground going from the Sending unit to the gauge.

Connect those and WE should be in business if the sending unit or gauge is not broken?

 

1 and 2 are correct, but 3 is not a "ground" wire. It should be a direct connection between the sending unit and the gauge. Make sure wire 2 is well secured and clean as the area where that wire is connected to the frame is commonly covered with dirt and crud after so many years.

If all three are connected as you say and the gauge still does not read correctly, you are correct, either a bad sending unit or a bad gauge.