Fuel gauge acting odd

[TonyPa]

I've never had a problem before and all of a sudden. I did leave my car get down between empty and a quarter of a tank. I went up to start it up and the gas gauge never moved at all.
I shut the car off, and started it up again and it still stayed down on empty.
I started it up at third time and then the gas gauge went up between empty and a quarter where it should be. It's done this two days in a row. Quite odd.
I typically never let my gas get this low...but I haven't had the car out Much. Is the fuel too low and the tank even though it's sitting on the level, and it's just getting aggravated?
after about the third start, the gas gauge works perfectly after that. Quite confused

[shogun]

http://bmwe32.masscom.net/maxf_website/gauge.htm

[TonyPa]

Thank you shogun, I guess that's my next project now. Some days I think this car makes me crazy.

[youngbimmer]

I have this problem too but I'm too chicken to try and do this fix. Solution? Keep gas tank above half full haha

[TonyPa]

I have this problem too but I'm too chicken to try and do this fix. Solution? Keep gas tank above half full haha

Im a little nervous myself. I just went up the garage, my garage is level obviously. It read between Empty and a 1/4 tank.
Drove to the gas station and on the level it read a 1/4 of a tank after I drove the car. Ugh.
I put it up to 3/4's of a tank. It seems fine.
But I'll check it when it sits overnight. That seems to be when it does it unless it's my imagination.

when you keep yours above half full does it NOT do it then?
The reason I asked this, mine has never done this before, and I don't ever let mine go below a 1/4 of a tank. This is the first time I let mine go that low.


.

[youngbimmer]

Im a little nervous myself. I just went up the garage, my garage is level obviously. It read between Empty and a 1/4 tank.
Drove to the gas station and on the level it read a 1/4 of a tank after I drove the car. Ugh.
I put it up to 3/4's of a tank. It seems fine.
But I'll check it when it sits overnight. That seems to be when it does it unless it's my imagination.

when you keep yours above half full does it NOT do it then?
The reason I asked this, mine has never done this before, and I don't ever let mine go below a 1/4 of a tank. This is the first time I let mine go that low.


.

Mine starts misbehaving at the last 1/4 tank, so I just keep it above that. I was hoping the solvents like B12 chemtool, techron, etc would make a difference, but they did not. Has to be manually removed and cleaned with electronic contact cleaner eventually.

[TonyPa]

Mine starts misbehaving at the last 1/4 tank, so I just keep it above that. I was hoping the solvents like B12 chemtool, techron, etc would make a difference, but they did not. Has to be manually removed and cleaned with electronic contact cleaner eventually.

I tried the same chemicals you did. I've never taken mine down below a quarter of a tank so I don't know if mine will behave the same. I usually get right below a half a tank and fill it back up. I just took mine off the 3/4 of a tank so I'm gonna check it tomorrow. And see what happens when I hit the key. Eventually I'm going to have to pull that out though and clean it. Which I dread doing

[CroughtonE32]

You know, both you guys are being forced to do the right thing here. It's a great idea to never let your gas tank go below 1/4 of a tank ever. You'll suck up a lot less crap into your fuel filter and eventually to the rail and injectors. So if having a sending unit not working right and it makes you put gas in when you're between 1/4 and 1/2 a tank because you're not sure where you are.....that might be a good thing. Fill Her Up.

[TonyPa]

You know, both you guys are being forced to do the right thing here. It's a great idea to never let your gas tank go below 1/4 of a tank ever. You'll suck up a lot less crap into your fuel filter and eventually to the rail and injectors. So if having a sending unit not working right and it makes you put gas in when you're between 1/4 and 1/2 a tank because you're not sure where you are.....that might be a good thing. Fill Her Up.

Oh absolutely I agree 100%. I Dont let my cars get down there a near a quarter of a tank. This is the first time I've ever really done that with this car. I just took to the store right now and it was fine went right up to 3/4 of a tank. I don't like sucking up dirt from the bottom of the tank I remember my dad preaching about that when I was younger.
also some of the electronic fuel pumps, on the gasoline to keep them cool or so I was told on some cars.
Like submerged and it

[kce1900]

It's not too difficult to get the fuel sender out, I managed to do this too. With help from the forums, of course. Here are some pictures:
http://bmwe32.masscom.net/sean750/fu...t/Fuelpump.htm
http://bmwe32.masscom.net/johan/fuel...el_sender.html

I really liked the idea of tying up the hoses so they don't get lost between the trunk floor and the tank. I also labeled the hoses so I knew which goes where. When you take the whole assembly out, the fuel hoses inside the tank have a tendency to get stuck at the edge of the tank, you really have to grab the whole thing, pull and turn at the same time. You don't see any rags in these pictures, but unless your tank is dry, you'll need them because fuel will be spilled.

In my case the center rod of the fuel sender was rusted. The rust was in the middle and that explained why my gauge preferred showing half full or half empty. I tried to clean that, but it didn't help, I ended up buying a new sender.

When I had this issue, I also had problems with my odometer. That was fun: road trips and neither a reliable fuel gauge nor a reliable odometer.

[E32FAN]

There is a second opinion about fuel - the Reserve Light.

Looking at page 6200-06 & 07 of the ETM, there is a separate switch on the B6 Fuel Tank Sensor that closes when fuel is low.

So if the fuel gauge drops to 0, you are good to go until the Reserve Light comes on, and then you need to think about finding a gas station fairly soon

[unity]

You know, both you guys are being forced to do the right thing here. It's a great idea to never let your gas tank go below 1/4 of a tank ever. You'll suck up a lot less crap into your fuel filter and eventually to the rail and injectors. So if having a sending unit not working right and it makes you put gas in when you're between 1/4 and 1/2 a tank because you're not sure where you are.....that might be a good thing. Fill Her Up.

The pumps have a filter, then there is the inline fuel filter. And if there is crap in your fuel, you better shop at a different fuel station! The amount of fuel in the tank is irrelevant, being low on fuel will not cause more stuff to be sucked up by the pumps.

[shogun]

The pumps have a filter, then there is the inline fuel filter. And if there is crap in your fuel, you better shop at a different fuel station! The amount of fuel in the tank is irrelevant, being low on fuel will not cause more stuff to be sucked up by the pumps.

Yep, the fuel pump suction points are at the bottom inside the tank, all floating dirt, rust etc is basically heavier than the fuel and will go down by gravity, same with water/moisture = always at tank bottom.

Plus there is one filter in each fuel injector = pre-fuel pump filter+ inline fuel- filter(s) between tank and engine bay + fuel injector filters
Injector.jpg
Fuel Injector components:
1. Top O-ring (Fuel Rail Side)
2. Fuel Injector Filter basket
3. Electrical Connection
4. Solenoid (Electromagnetic coil)
5. Pintle Valve return Spring
6. Pintle Valve
7. Engine Side O-ring
8. Pintle Cap
9. Pintle Seat or Fuel

[shogun]

Where is TonyPa? Last time seen on the forum May last year.

[SergeBMW]

Not sure, hope he is ok. Wonder if he ever got his issue fixed. He usually writes back.

His issues could have been either the gauge or sender, a cluster test should rule out the faulty gauge correct?