Fuel Guage

My fuel guage is on the fritz. when the tank is full it will read full, but at any onther level it will read 3/4 full. the low fuel sensor will come on when i'm low but it will flicker between full and empty.
need some input.

1. bad fuel tank sending unit,
2. bad float in the fuel tank
3. Bad fuel gauge
4. bad wiring from sending unit to fuel gauge
to check system you need a GOOD DVOM and the specs for the sending unit in ohms for full and empty

I think this might narrow it down out of the list, when i'm in park the needle will go all over the place, but while im driving it usually stays in one place(usually around 3/4 full ) unless my tank is almost empty

Its the sending unit. In Canada they have a hidden warranty for this due to some of the fuel additives they add up here. GM believes it is the fuel additives causing the problem. I had mine replaced no charge a year out of warranty. Had to run the vehicle through one tank first with an additive they put in the tank. If the problem still existed after the two weeks, I was to come back in and have the sending unit replaced. I just had to fill out a short questionaire at the dealer stating what grades of fuel I used and what brands.

Check out this post I added, It contains infor on the level sensor kit. For your year (2000?), This kit will work on 2 door models. For 4 door models, there's a different kit, #25314258.

http://www.automotiveforums.com/vbulletin/showthread.php?t=368013

you might want to check your fuel injectors, i just checked the pressure on my fuel lines since mine was doing the same thing. and found that one of my valves are blocked and i am pushing 60 instead of the 5 or 6 that it should be at an ideal, so since that is happening the computer is getting all out of whack trying to compensate for it.

you might want to check your fuel injectors, i just checked the pressure on my fuel lines since mine was doing the same thing. and found that one of my valves are blocked and i am pushing 60 instead of the 5 or 6 that it should be at an ideal, so since that is happening the computer is getting all out of whack trying to compensate for it.

This would affect your mixture not your fuel gauge.... Looking at your profile, you show a 2001 blazer.... This is supposed to run at 60 psi, (56-60 to start, 61-65 at running) If you were to drop your pressure down to 9 psi it would not even start. The only 4.3's that run that low are the 87-95 TBI motors (you have CSFI) that run at 9-11 psi. You don't have a clogged valve or any sort. Infact the only valve between your tank and the intake is a check valve that maintains pressure to the line.


In his case it's the sending unit in the tank.