I searched and came up with one post. I've read that I should have a 22gal tank with a short bed. When I fill up at "1/8" of a tank or "empty" I can only put 17gals at most.. My fuel range says 347miles when I fill it up but at most I get 200ish and fuel economy says 14.4. The truck has 172k miles on it when I got it, it had 150k and averaged 17.5mpg from fuel used to mileage.. I also changed plugs and wires in the last 10k miles, what is the deal?


Any help would be sooo greatly appreciated!

 

Your truck has a 26 gallon tank. Verified by Mitchell On-Demand, and they get their info directly from GM.

 

cool thanks, so I guess my fuel sending unit is going bad or something??

 

Possibly so. The GM sending units don't have the best track record in the world....

I'd say get two 5 gallon cans full, and run your tank out. (unless you've got an aftermarket pump in the tank). Then you'll know exactly where you stand with the gauge, and you won't be stranded.

BTW, GM stepper motors in the instrument clusters have a bad track record too.....

 

kick *** thanks AK I <3 you!! lol Gonna do this tomorrow... What should I check first sending unit or Stepper motor or how would I tell either?? Sorry for so many questions I really appreciate your time.

 

Well, if you have a good scan-tool available, you can read the PCM and see if it matches your gauge. If yes, you've got a bad sending unit, and if no, you've got a bad stepper motor. Another tool to use is a signal generator. You unplug the sending unit, and plug in the signal generator. You command the gauge, and see if it corresponds correctly. If it does, the sender is bad, and if not, the stepper motor is bad.

 

I don't have any of those tools... =(

 

Borrow a cluster from a buddy. Swap for a few days. If it still isn't working right, you need the sending unit.

If you don't have tools, you just need friends.

 

Lol roger that, there all at Tx2k12 just have to wait.


Thanks again

 

been driving the truck for a day or so on E with light on, 60miles or so I may get 300 to this tank.. Not sure why the truck is sucking A$$ on MPG but that's another thread lol. So still not sure what it is just tells me the gauge isnt right..