: Fuel Level Detection

12-14-10, 02:23 AM
What exactly determines how much fuel is left in the gas tank? Whatever it is, mine is dysfunctional, since it will show 2-3 bars of gas on the dashboard, while I actually have no gas.

Is it a sensor in the gas tank? Can I replace it myself?

sinatra caddy
12-14-10, 08:32 AM
there is a float on your fuel pump that moves up and down depending on how much fuel is in the tank. they are not always accurate. this is not the first time i have heard of two bars on the guage and the tank is empty. i had a 97 deville that would read 3 and ran out of gas. you can try a fix by putting techron in it. i just did it to my fleetwood and now the car runs better and the fuel gauge isnt stuck on full.

12-14-10, 09:13 AM
There is a post in here that someone posted a fix for this problem. you have to drop your take, take out the thing and solder it. some problem with the variable resistor or something.

12-15-10, 09:56 AM
it is called the sending unit. I just had mine replaced for the same reason along with the fuel pump.

01-02-11, 07:47 PM
How much did you pay in total for the sending unit and fuel pump, mjs182004?

01-03-11, 11:28 AM
You should never run your car all the time with 2-3 bars left because this will shorten the life of the fuel pump , just my two cents

01-05-11, 10:25 PM
The resistance value of the sending unit changes with age - theres an add-on calibrator available online -
It's listed for a Caprice, but it works for all full-size GM either analog needle or digital bar graph.

01-06-11, 08:43 AM
at $20 that sounds like a pretty good deal. anyone know how well it works?

01-06-11, 08:59 AM
All of the B/D-bodies have this problem. Welcome to the club. :D

There's a tech article on the Impala SS forum about fixing it. I'm browsing on my cell phone right now but when I get out of classes today I'll dig it up (unless Jay beats me to it lol)

01-08-11, 03:04 PM
would this also solve the problem of a fuel gauge that reads what it wants to...in my 95 fleetwood most of the time it reads full no matter how much fuel is in the tank. sometimes it reads the correct level and when you turn the car off and back on its full again. sometimes it will show proper level, then while driving goto full sometimes bounce back and forth.

01-08-11, 03:22 PM
I think that's a different problem... my parents had an Olds 88 that did that (showed whatever the heck it wanted to on the gauge until you shut the car off and turned it back on). Not sure how that was resolved though.