92 318i Fuel gauge stays at empty

[MasterIvanPR]

I bought the car not too long ago as a project car. Now my problem currently is that gauge is marking empty all day long. Now it turns on the empty light. I did the instrument panel check and the gauge went up Nd down just fine. I am a automotive tech student at UTI and currently in electrical. I would like to know for any clues/ideas/fixes/recommendations/suggestions to fix this....if not possible way to use another sensor or a aftermarket solution. Any help would be appreciated


Thanks guys...love the forums btw

[slocar]

Sometimes if the car has been refueled with the key in the igntion, the gauge screws up. With ignition on, try pulling fuse 31 under the hood for about 5 seconds ... see if that gets it back to life before you start replacing things.

[IhaveanE36]

Same problem here. 98' 328i. Before, my fuel gauge use to flutter up and down and then back to normal, now, it stays @ empty w/ the orange warning light on constantly. Been driving like that for ..... 3/4 of a year now ...

I replaced my fuel level sensor (behind driver seat) and still nothing.

OP, if slocars' procedure does help, PM me, or if anything else works that you find out, PM me lol.

Btw, I have a feeling that I (and possibly you) may have a wiring issue thats inbetween both the pumps in the rear under the seat. When my dads' friend who's a mechanic played w/ the wires, the gauge shot up to about 3/4 fullish.

[MasterIvanPR]

Thanks soclar. I will deff be trying that today after class to find out. And will post the results.

@ihaveae36
Yea possibly could be a bad wire I printed up the info for the proper resistance needed and will be testing the sensor and wiring.

[Joylove]

I think the wiring gets cut/falls off the fuel pump. A fairly common problem with a few guides on the internet.

[MasterIvanPR]

@joylove so ur saying that its quite common that the wiring comes off the sensor?

[Joylove]

Yep.

http://www.unitedbimmer.com/forums/b...placement.html
http://www.bimmerforums.co.uk/forum/...roblem-t73412/
http://www.bimmerforums.co.uk/forum/...-again-t59048/

[MasterIvanPR]

Thanks jaylove.
I'll check this info when i get home from.school since I'm on.my mobile

[MasterIvanPR]

Progress is none guys. after messing around with it for a few hrs. I got nothing. Initial inspection showed that the live cable to sensor 2 was sheered clean off. spliced it and made it nice and neat. checked voltage at all sensors and all are with in spec. Now what i did find was a strangler wire. All alone. it wasnt intertwined with all the other cables. so i tried tracing it back but nothing i disappears into the abyss of the car. I will be looking up the intere wiring diagram for the fuel pump 2 dash tomorrow Using AllDATA and see if i make progress in the coming days. I have a temp idea to see if the sensor indeed do work and willl be testing it tomorrow

[MasterIvanPR]

Anyone have anymore suggestions

Sent from my HTC Aria using BF.com

[flyfishvt]

You have two level sensors. If your guage is working like they described then its most likely the sending unit in either the passenger or drivers side. Certainly do the Fuse 31 test first but I would say all those who posted above are eventually going to find its the sending unit.

[Joylove]

Find out what the stray wire is by inspecting the fuel pump diagram in the schematic? The wires are all colour coded, and they shown where they connect to around the car also.

[IhaveanE36]

MasterIvan, you died on us duuuuuuuude. Did ya' solve it? ?

[MasterIvanPR]

Yea basically what happens is this....the fuel pump/sender and level sender on driver side are wired are wired in series which means that if one leveler is bad then neither will work. So replacing one won't fix the issue. In my case the driver side one is bad cuz when I checked its resistance was below specs. What I did was on the fuel pump side disconnect the sender and get a 12v battery and send power to the connector going away from the pump and see if the gauge shoots straight to full then get some resistor from radio shack and then test them and see what which resistor gets u a 3/4 tank,1/2 and one quarter....in doing this u check the wiring and you pinpoint the problem at the same time. But I'm pretty sure its the sender on the pump but just like me. The driver side sender is usually fine but since the fuel pump assembly has the sender integrated into it. Its the one that gets most abuse since it is the PRIMARY SENDER and driver side is the SECONDARY.

If there is anything else I can do to help anyone then ill try. Hope my experience is helpful

[ManWith16Valves]

Guys, should the resistance on both senders be the same or not? I have 1/5 of tank (yellow light isn't on) and one resistance on one sender is ~115ohms and on another ~10ohms. Is it wrong or not?
Why did I start to look into this? I've noticed that when going uphill fuel gauge drops noticeably and doesn't rise back. Any ideas?

[shogun]

Old story, but just to give some info here that the search finds a solution in the end.
When I filled up my car sometimes the fuel gauge would not show full after I had filled the tank. Red light on = tank empty, then it suddenly jumped back to full while driving, then back to empty. Searched and found:
it could be the level sensor which sits inside the lobe of the tank. Remove the back seat and you will see two panels; one on each side. Go to Realoem.com to see arrangement of pump and levels.
In my M3 case it looks like this http://www.realoem.com/bmw/showparts...g=15&lang=enUS
I also read in another thread: "I'd start with pulling and reinserting fuse #31, just to make sure it's not the classic E36-refueling-with-ignition-on-confuses-the-fuel-gauge-syndrome."
This was not the case on my car. Ignition was off when refuelling and key was even out of ignition, just to comment to above hint.

This happened meanwhile 2 times, weather/climate is warm, so it could not be cold temp causing it. In the end, after some times switching engine on and off within 1 day, it finally worked fine. As if the system is first confused by a fuel refill and needs some time for adjustment. and here the solution I found on an German E36 Forum. Apparently it is unfortunately often that the wire(s) of the fuel gauge sender unit inside the fuel tank get's lose as shown here. Resolder or replace the old wire and the problem should be solved.

http://img692.imageshack.us/img692/8...pgaugeprob.png
http://imageshack.us/photo/my-images...pumplevel.png/

Other comments I found:
could be both senders are bad, one on fuel pump and other stand alone, if one works you will get a reading on gauge, if not wire. When I bought my car it had set for over a year and when I turned on key showed no fuel, put in 5 gals and still no reading. I could not get it started and so I replace fuel pump complete with sender and wala fuel gage worked and car started right up. I'm reasonabily sure the sender only on drivers side is probably bad also. I guess it could be the wires.
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I used Contact Cleaner and a course-surfaced business card to clean the contact surface of the sweeper on the fuel level sending units.

My symptom set was that the car would display E after a fill up, then after a while it would jump to the then current fuel level and drop normally to E as I consumed fuel, then remain on E after filling the tank. I had to reset the odometer on each fill up to keep track of the gas in the tank. This is the easy way to deal with this problem, by the way -- fill the tank full and reset the trip meter, then drive 300 miles and repeat.

I eventually got to the point where the car displayed E for an entire tank of gas, so I took the sending units out and cleaned the sweep contacts. BE VERY CAREFUL TO NOT BEND THE SWEEP CONTACTS. There are a pair of contacts on very thin arms that slide over a pad of fixed contacts. The car sees the contact of the sweep and fixed contact pad and measures the resistance to arrive at the fuel level. It was pretty easy to clean the fuel level sending units. The right side sending unit also houses the fuel pump. If you are willing to fill the tank and reset the odometer, then drive 300 miles and repeat, you can ignore this problem for a very long time.
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Fuel level sender, pump side, has failed open circuit.
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Sounds like the contact pad and sweep are dirty. This can make an open circuit. There isn't very much on the fuel level sending unit to go wrong, and dirty is at the top of the list.
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I removed the fuel pump, covered the opening with a wet tea-towel, let the pump dry, and repaired the broken cable inside. Problem solved.

[flyfishvt]

My 97 328 was doing this. It turned out to be broken wires right at the connector on the sender in the return (non pump) side of the tank. I cut the connector off and soldered on an replacement I had in my junk pile.

[shogun]

the imageshack picks I posted before do not work anymore, here new
http://www.photo-host.org/C8t
http://www.photo-host.org/C88

Model: BMW E36 (3 series) including BMW 318ti produced from January 1995
Complaint:
Due to the formation of a non-conducting deposit on the conductor surface of the fuel level sensor, the fuel gauge does not read full after re-fuelling, or the fuel gauge is erratic. Remedy:
Remove and replace both fuel level sensors with “Gold system” sensors.
Fuel Gauge Stays Empty after Refuelling/Fuel Gauge Erratic
Model:BMW Z3 Roadster/coupe, BMW M roadster/coupe (E36/7). Vehicles produced before December 15 2000
Complaint:After refuelling the fuel gauge will stay on empty or the fuel gauge is erratic. This is caused by a non-conducting deposit being formed on the conductor surface of the fuel level sensor. For the Z3 from September 1998 and the M roadster/coupe FC 2 (Fuel sensor voltage plausibility) will be set in the Instrument Cluster.
Remedy: Remove and replace the fuel level sensor with a ‘Gold system’ sensor referring to repair instructions 16 12 000.
Model:
BMW Z3 (E36/7) produced from September 1998 to April 1999
Complaint:
After refuelling the fuel gauge reads ¼ full, and will then move extremely slowly to read full. This is due to a software error in the Instrument Cluster.
Remedy: Re-code the instrument cluster using DIS CD Version 18.0 or later:
-Select Coding/Programming/ZCS Coding/E36/Recoding/Kombi and then follow the on-screen instructions to complete the coding process.
-Recoding the instrument cluster will start an internal day counter. If the test3.1 contains a value greater than 0 indicates the instrument cluster will already contain the fix.

More interesting stuff here
https://www.bimmerforums.com/forum/s...el-Level-Issue