gas question
 

hi everyone.. i have a 01 4.4i. when my tank reads around 1/4 tank or range 80miles it runs out of gas.. i did a search and some people are saying pump some saying sending unit some saying filter..idk.. i know my gauge is reading correct.. any advice ? thanks in advance

I would bet fuel pump.

You have two inside your one saddle tank. One pumps fuel to the other side (the one that is most likely bad) and the other pump sends fuel to engine.

How much fuel will it hold when you fill it up when it shows you have 90 miles before it runs out?

i cant remember how many gallons ..but i usually put 60-70 dollors worth.. gas over here is like anywhere from $3.60 to $4.00

There is a thread on bimmerfest E39 sub-forum stating that using Techron Concentrate help fix his gas gauge problem.

If your cluster is UNLOCKED...you can do TEST 6 and see if one of your fuel level senders is on the fritz.

TEST 6 has 2 screens...the 1st shows what the left & right fuel level sensor is reading + the approx amount of fuel (in liters) are in the tank. The 2nd screen shows approx amount of fuel in the tank and also indicates if each sensor is sending data correctly by indicating:

1. PHASE 1 - both sensors are OK
2. PHASE 2 - one sensor is faulted
3. PHASE 3 - implausible input/contents can't be computed (at least one sensor is faulted)

i dont think my guage is messed up cause i reset my trip meter and im only getting around 220miles till it runs out of gas

What I am suggesting --when the tank is almost empty, fill it up and see how many gallons it takes from what it reads on the pump. That will tell you if the tank was near empty or not, based on the amount of fuel your tank will hold when it is full and how much it took to actually fill it.

Q7 can correct me if i am wrong, but the E53 tank holds about 24.6 US gallons of liquid (gasoline), so, at the pump, if you manage to squeeze into the tank 23.6 gallons (hopefully the NY pump is calibrated correctly), you only had about 1 gallon of fuel slushing around... this is what bcred is suggesting... if your MPG is about 15 , then for the 80 miles left on the computer screen, you should have about 4-6 gallons of fuel left in the tank, and if you fill up the tank only 18 gallons to full, then you have those 4-6 gallons for real... if you pump 24 gallons, while your computer is reading 80 miles to empty, then your level sensors are lying to you...

there is only one live pump and the other one is a siphoning pump, does not have electrical parts in it... the pump with electrical motor is on the right side of the car, that is the one that sends the fuel through the fuel filter to the engine... the passive siphoning pump sends the fuel from the left part of the saddle tank to the right side... sometimes, if the left side has fuel, that side will register decent amount of fuel but the pump can't siphon it because of debris, or other issues - thus you have a reading of fuel but no fuel gone to the active pump to go to the engine... therefore, if you do what Q7 suggested, you can see the amount of the fuel in left tank, and if that is the amount that is reported to the computer but not picked up by the pumps...

a little bit of homework will help you narrow down the issue and avoid unneeded expenses...

thanks for the response .. when the car says 80 miles left and i fill it up it then says 350 miles left give or take