Well since I bought my loved blazer the gas gauge hasn't worked. It would either be on full or empty. Recently I've noticed it has been fluctuating around, and right now I think the gauge has actually been working. I put fuel injector cleaner in a few weeks ago. I'm nkt sure if that has anything to do with it. I think its a wiring problem but I know blazer have this as a common problem. Any thoughts as to what it could be?

 

The fuel sending unit is most likely the cause.

 

either that ^^ or possibly a ground...

 

if your truck has 100k miles on it or more, just go ahead and buy a pump. You're going to replace it anyway sooner rather than later, and that will fix your gas gauge problem.

 

Yeah, it has 108,xxx miles. I recently changed the LIM gasket,and since then my gauge has been working correctly. I'm not sure if those 2 are related.

 

Strictly coincidence, they are not related. As mentioned, the fuel level sender is probably on its way out. If you unplug the module connector, the dash gage should indicate past full. If you ground the purple wire in the harness connector, the dash gage should indicate below empty. The level sender can be serviced separately but requires removal of the tank and fuel pump module. At 108K, if you drop the tank, you might as well replace the entire module. AC Delco or Delphi only

 

Yeah, that's what I figured. Thanks a lot for the help everyone!

 

I'm seeming to have the same issues with my blazer , but not the whole full or empty issues just the fluctuation . I fill up and drive under 20miles and it will be at a quarter of a tank if not a little less. The pump was just changed under a 2 months ago , and im guessing the sending unit was also replaced ? Can't seem to find any real info as to what tank size our 4dr's have I get 14-18 not really sure what to believe, just know that at every fill up I dont fill up past 14 gallons .

Chi_Town

 

What year is it? My 98 has the metal 18 gallon tank. Some have a plastic tank (hold's a little less).

 

My '95 4 door also has an 18 gallon metal tank. The 2 door tanks are shaped differently, but I'm not sure it the capacity is different.