Fuel gauge issues

[tim eh?]

go to a salvage yeard, take out a fuel pump sender assembly, check the resistance of the sender yourself and if ok, install that bad boy in your car

My vote is the fuel level sender. Happened on both of my e34's. Fixed by one from ebay.

I don't understand how you guys conclude this - if the obc gets an accurate reading then how can the sender be faulty?

[632 Regal]

how do I check the OBC for fuel content?

I don't understand how you guys conclude this - if the obc gets an accurate reading then how can the sender be faulty?

[bubba966]

how do I check the OBC for fuel content?

My friend is using the range function along with the knowledge that she averages 20mpg.

Which is why I don't see how it could be the sender if the OBC is getting a signal saying it's not empty when the gauge says it's empty.

Although I'm kind of recalling that she says it's either saying it's got a half tank or is empty. Maybe the sender is going wonky and is giving enough of a signal to the OBC for it to think it's half full while the cluster is getting a worse signal that says it's empty?

Should try to just pull my sender out of my M-Sport and slap it in her Touring...

[tim eh?]

I know there are 2 types of pumps, is the level sender the same?

how do I check the OBC for fuel content?

test #6 and #7 with unlocked OBC (#6 is immediate, the other is approximated... i think)

edit *- mine reads in litres (i think)

[632 Regal]

my range option says almost exactly what the OBC says according to my calculations and the guage that no longer works. Sounds like the sending unit is fubared in some way now.

My friend is using the range function along with the knowledge that she averages 20mpg.

Which is why I don't see how it could be the sender if the OBC is getting a signal saying it's not empty when the gauge says it's empty.

Although I'm kind of recalling that she says it's either saying it's got a half tank or is empty. Maybe the sender is going wonky and is giving enough of a signal to the OBC for it to think it's half full while the cluster is getting a worse signal that says it's empty?

Should try to just pull my sender out of my M-Sport and slap it in her Touring...

[Bo525i]

Well I swapped mine for one from the salvage yard, seems slightly less erratic but still drops to empty about 50% of the time compared to the old where it was 85%..

My next move is to try the fully working sender from my 525 and to see whether I still get erratic behavior.

I´ll keep you posted (½ tank so I gotta use most of that first! )

[Kibokojoe]

yes it helps to clean the wires. I use a cotton ball and contact cleaner

[632 Regal]

pumps on top, fuel level shouldnt matter?

Well I swapped mine for one from the salvage yard, seems slightly less erratic but still drops to empty about 50% of the time compared to the old where it was 85%..

My next move is to try the fully working sender from my 525 and to see whether I still get erratic behavior.

I´ll keep you posted (½ tank so I gotta use most of that first! )

[Bo525i]

You still have to stick your hands into the gas to release the pump/sender unit from the base.. So I´ll wait!

[Bo525i]

So, finally got around to changing fuel pump and the sender units, not from my 525 as the pump differs but from a 95 540 @ the salvage yard.. Now the gauge works like it should and as a bonus the obc now reads below 8 liters on obc code 7, got a reading of 4.4 liters after installing the new units (not on code 6 tho, that still reads 8 liters) Never had it do that before!

Another thing that I found was that my old pump wasn´t seated properly lacking about ½ inch on the right side looking into the tank, so be thorough and seat it really well by pushing a bit hard when you have to reinstall the pump!