out of fuel.

[~R~]

I have a 1990 535i and for sometime now my obc and my fuel gage seem to be out of sync. normally when I fill up about $20 worth of fuel. the gage shows that I have half of tank and my obc will read that I have about 185 miles to go on that fuel amount.
as I drive through town, (Los Angeles, CA) I notice that my fuel gage will drop dramatically as if I was running out of gas real fast. I'm talking about perhaps 20min to 45min after I fill up that my fuel gage will show that I have very little fuel left in the tank. Today 12/14/04 I believe I might have ran out of fuel... my check engine light came on and the car felt as if it ran out of fuel. it actually happened like this... as I was on the highway the car studdered and I noticed the check engine light came on, I was able to drive for 1/3 of a mile get off the highway and let the car idle for about 5min till when it shut off by itself.
my question is, what is/are the symptoms of the car when/if you run out of fuel?

no overheating, no smokes of anykind everything looks normal.

 

[epj3]

Thats becuase your gas tank has a "reserve", which is why most gas gauges have a F for full and R for reserve, its usually a 2 gallon reserve and is when your light comes on.

I think yours might say 0, 1/2, and 1... but even so, I'm sure its correct. Try it from a full tank.

 

[~R~]

I have filled it to where it does not take more gas, and I get the same reading.
thanks for your reply.
have you experienced running out of fuel?
if so, what are the symptoms?

 

[Chesty Bonds]

Er, the engine stops following a series of shudders from the engine as it becomes starved of fuel.

 

[Average Jae]

when you have no gas, the car putters for a bit, and turns off. there wouldn't be any significant external signs of having no gas.. the car just won't run.

if your fuel gauge and such are messed, always fill up all the way, and reset your odometer. then gauge your milage from there. i suualy get 350+ on a full tank, so i gauge it that way, but in the winter, i used up over 10 gallons for around 100 miles.. short starts in the cold really burns up the gas i suppose..

 

[~R~]

thanks Average J, for your reply.
does check engine come on necessarily when one runs out of fuel or is that a sign of something else gone wrong?

 

[Average Jae]

no biggie R, dont' quote me on this, but bmws have check engine light come on when there are fuel issues also. it's a vauge light that you have to find out the error code to figure out what exactly is wrong. but it came on a few time on my parents' truck when you don't properly close the fuel cap, i was on for a week or so two or three times. of course this always happened right after my dad filled up the car, but it was never his fault. go figure..

this maybe an urban legend, but i heard that w/ fuel injection cars, when you completely run out of gas, you have to have the dealership reset something before the car can start again. any truth to that rumor? or was i just doped into not running on empty? ^^

 

[~R~]

Thanks for your replies guys.
I guess I was out of fuel.
Just filled her up and after a couple of cranks she started up like a champ. now I'm back on the road. [driving2]


talk to you guys later.

 

[Big Daddy]

No Jae you do not have to do anything special when you run an injected car out of gas. However because the fuel pump is in the gas tank, it is the gas that cools the pump and running your car out of gas will negatively affect your fuel pump.

 

[BMW-FW26]

Only on a diesel does it suck when you run out of gas. (Stupid Volkswagens.) I've notice on my 325is the computer doesnt match the gas guage, but the guage is correct.

 

[bahnstormer]

there is a way to configure the obc's gas estimate.
The OBC knows two modes: Locked and Unlocked.
When you get your car, it's probably locked. In the locked mode, the hidden functions will refuse to work.
In the unlocked (free) mode, the hidden functions can be accessed.
Please be carefull to use these functions, especially function 21: This one resets all OBC data !
To change the lock/unlock mode, you have to execute function 19, see the table on this page

The average fuel consumption value can be calibrated from the OBC. Function 20 is used for this.
Fill the fuel tank to the maximum. Reset the day trip counter. Run the fuel tank nearly empty and fill the fuel tank again to the maximum. This will give you the fuel consumption.

New Correction Value = Old Correction Value * OBC Fuel consumption (in MPG or l/100Km) / Actual Fuel Consumption (in MPG or l/100Km)
or
New Correction Value = Old Correction Value * OBC Fuel consumption (in MPG or l/100Km) / Actual Fuel Consumption (in MPG or l/100Km)
Please let me know which one, I didn't check.

function 7 might be of interest to you
7 35 T:MTL Varying Fuel in tank as a % of full. Measurement


http://home.iae.nl/users/bts/obc.htm

 

[geneo]

check engine lt will come on because the dme sense miss fire as the car is running out off gas