why is it when i push onmy brakes my gas guage goes down and when i lift up or go up a hill it goes up. same with turns. if i go right it goes up if i go left it goes down. not all the way but about a 1/8 of a tank one way. so when i turning left then right immediatly my guage moves a 1/4 of a tank. why is that? does anyone else's do that. i had a 86,88,84 z28 and they all did it too. is my fual guage shot or is it the sensor inside my tank that i don't want to go near?

 

Im not being a smartass when I explain this but , Your gas in your tank is moving around at the same time the little float thingy that tells you how much gas is in your tank is going up and down .

Think of it this way .... If someone were to place a bowie on the shorline of a beach and made the line holding it down extend through the middle of the bowie and go out the top and end in mid air above the water when no waves were present . Each time a wave would come in the bowie would go up on the line , then back down when the wave broke . Then imagine , if there were a big giant floating around in space , if he were to give the earth a bitch slap with his hand on one side all the water on the earth would be moving to the opposite side . I dont know how I came up with this wierd analogy :biggrin: It's early in the morning :biggrin:

Also notice , after you finish getting gas , it wont move up in down for awhile , until you use up some gas , this is because the tank is full and the ball is as for up as it can go to that line or whatever is holding it down .

 

that's the same mine does too. Except when I go right it goes down.
Far as I know the sensor isn't in the middle of the tank, so when you go downhill or hit the brakes, the fuel sloshes to the front, lowering the level in the back of the tank where the sensor is likely at, therefore it starts reading less fuel. when the g-force is pulling backwards, the fuel goes back and then you read more.

Just floor it and never let up. You'll stay on full forever.

 

Beat me by a minute!

 

 

Do alot of people have this problem? My bird doesn't do that. I replaced my pump and sending unit recently, maybe that has something to do with it?

 

Yes the pump and sending unit do have something to do with it. When the pump in my 85 was replaced the reading on the needle actually got worse. I can't run mine down to 3/8ths of a tank (otherwise I'd be stuck on the side of the road). The float level is adjustable but it requires dropping the tank. I can live with an inaccurate needle (that's why I like the "whine" my pump gives around corners when I'm low).

Also, I think the later years got better baffling in the tank to minimize the problem.

 

i understand that gas does move in your tank, i'm not an idiot. my question is some do it and some don't. new cars don't do it(4th gens) and others as well. does the sensor have to be replaced to fix the problem. has anyopne had that problem and fix it?

 

I think it was just a case of GM **** poor designing back in the day. You may be able to eliminate the problem by installing a 4th gen pickup and pump but I'm not sure if it can be done. Most people just live with it because the effort to fix it is sooo great and the results are minimal.

 

Yeah, it wouldn't be a bad sensor. You'll know the sensor is bad when the needle pegs "FULL" and never goes down. It actually goes about a 1/2 inch -past- the full mark. You can't just buy a new sensor for cheap, either... GM wants $300 for one. And as you know,you have to drop the tank to get at it...

 

that's the problem, i don't want to drop the tank unless i know i can fix it. i don't like turning and accelerating fast and then slowing down then try to figure out what my needle is trying to say. i have to wait until i'm on flat land and moving steadily. it kinda sucks actually. has anyone ever tried a 4th gen sending unit. i have a 91 rs and gm doesn't sell just the guage by itself being it is connected to the others. Gm told me they sell the whole dash cluster for around 350.00 with the tach, speedo, guages and all. anyways, if anyone has a solution and tried to make sure it works let me know, please!?!?!?

 

Is it real hilly where you live ? .... Mine does it , but not to the extent that it bothers me .

 

yeah, i live in pennsylvania in the "endless mountains range" it sucks and i never know how much fuel i have when i'm driving , only when i start the vehicle. i've been driving my camaro's for a while now so i have a pretty good idea on what it does and how full it is, but yeah it bothers me

 

Yeah, people complain about this alot. Nothing you can do.

SOME newer cars, high end cars, have a device that will sort of "ignore" a very short change in resistance from the float. So when you go up and down hills, the gauge won't change until it thinks the level has actually gone down. I'm not too familiar with these systems but they do exist.

Also, i know this wasn't brought up but people always say that their gauge just plummets after you reach about 1/2 a tank. Well, think of the thirdgen tank as an upside down triangle. The upper half actually holds more fuel than the lower half. So when your gauge reads 1/2 tank, you really have about 1/4 to 3/8 of a tank.