Erratic fuel gauge , advise needed .

[connorb16]

Hi Guys, hoping you can help , I have a e30 316 f89 with the M40 engine , the petrol gauge seems to be a bit erratic i.e. if I brake it goes up and if I accelerate it goes down ? im not to sure where to start has this is my first e30 so it is all new to me , I have found some paper work to say it had a new fuel pump at bmw a couple of years ago , would appreciate all advice , thanks

[smithy318i]

How much does the guage move ?

[connorb16]

Well at the moment its on just over 1/2 a tank and goes up/down a quarter either way .

[cro320]

SI board batteries dead or you need to thighten small screw behind gauge (remove cluster)

[connorb16]

Where would i find the SI board batteries ? you will have to bare with me im a bit of a novice , thanks

[carlos_320i]

Mine did that and I changed the clocks If I had of known this it would ov saved me £30

[DaveD]

maplins sell the batteries,but check first to see what type the are as some of the later ones had the flat sort...and if you post an email address i have a how to pdf i can send you

but maybe you just need a new sender?

[slinky2000]

DaveD, send me that link there too. stefan_ray [at] hotmail.com

[DaveD]

sent

[brian325i]

sorry for interupting your thread but my fuel gauge reads full most of the time..give it a few slaps and it gives correct reading but still varies a small bit but hit a bump and it goes to full again????????

clocks or the sender in by the fuel pump or what is it?its common cause my friends is exact same bmw engineering always make you feel good by pretending you have full tank of petrol

[connorb16]

I would appreciate that pdf, I have managed to remove the cluster I tightened a 7mil nut that holds the gauge in place im hoping this is what you mean ? took it for a drive and still doing the same , so I took it apart again found the batteries they are two round tubular ones they look ok but they don't look that easy to remove has the ends look like they are soldered to the contacts ? thanks for your help ps E~ MAIL sent via pm thanks appreciate your held DaveD

[DaveD]

sent

[glenbat]

Brian325i I'm not certain on this so I may stand corrected, I thought i heard once that some E30's have either 2 'tanks' or 2 sensors, and if one fails you are actually out of petrol when your gauge reads half full? I had a prob like this on an old 318iS as sono as I got to half full on gauge, she ran out... i might be completely wrong so if i am apologies as it was several years ago

[Sy_325]

any chance i could get this pdf??

much appreciated

[slinky2000]

I'll post up a link when I get home this evening and uplaod it to a server

[bam2002]

I had the same problems on a car. It turned out to be a ground fault. So I had to track down where the ground attached under the dash. Plus back at the tank under the seat.

[B51ngh]

DaveD can you send me that link also please? its balsinghg - at - hotmail.com

[tannerman8807]

Dave D you got PM::