I really dont want to over troubleshoot this one so I decided to bounce some ideas off of you ppl first. Short history, this car sat outside and in a garage for 2 years with an empty fuel tank. Now that I have her back and running, I just cant get any other reading that E on my fuel gauge. I want to avoid dropping the tank to check it... Is it really possible that the float in the tank seized up and got stuck in the empty level? Here are some short facts and troubleshooting.

> Changed from FI to Carb so the original pump wires have been cut
> Installed a new external pump with its own power and ground wires
> Wired the pink sender wire and black ground back to the tank wires, the original power wire wont put out voltage for some reason so I capped it just in case
> Without the fuel sender wire hooked up the gauge reads completely full, with it hooked up the gauge reads completely empty

Does the sender need that power wire hooked up from the original pump? Is it possible that the gauage is jacked up? I just really dont want to drop that tank.

 

it sounds like the sender since it is a resistor based design. empty=full resistance or E on the gauge.
, full gas tank or no connection = zero resistance, also equals full on the gauge.

 

I think that's backwards. E=0 ohms (shorted to ground) F=90 ohms (or more). It could be the sender or a short somewhere between the gauge and the tank.

 

I take it back, I don't want to accidently give false information until I am reconfirmed.

 

If there is a break in the circuit (infinite ohm), the gauge will show a full tank (and then some).

If the the circuit has a ground fault in it, the gauge will read empty

The exact opposite of the temp gauge.

jv9999 is correct.

 

oh good then what I typed was wrong but what was in my mind was correct , in my last post I mentioned when I disconnected the harness it would peg full. but then I edited it! thanks for clarifying deadbird. (a living bird usually is more exciting btw)

 

either the sending unit is bad or maybe the gauge itself. i would go with a new/used gauge first since its the easiest to change. if thats not it then i would say drop the tank and replace the sending unit. OR cut an access hole in the hatch area. and replace it. << thats a heated debate answer. While you are in there i would go ahead and replace the fuel pump as well. Might not need it now, but you may in the future. do it all at once. Thats my 2cents.

 

We already established that the gauge works (pegs at full when disconnected) so the blame is now on the sender in the tank.

Lou

 

If you need a new sending unit we have them in stock.Here's a link to them.

Firebird Sending unit