Fuel gauge not working....

RedRummy · January 13, 2007, 12:43:58 AM

My fuel gauge isn\'t working (as in it always reads zero fuel)

I usually judge when to fill up by the number of Kms travelled....

Is it owoth me getting it fixed (think its just a sticking float) or is it likely to be pretty useless anyway - I know all the other stock gauges are unreliable too...

:3gears-lh

Prof · January 13, 2007, 12:48:10 AM

Earth has come off somewhere or the signal wire from the sender.

When I changed my fuel pump, there wasn\'t an extra wire to tie to earth, and consequently the fuel gauge regisitered 0. A quick fix for me was to earth one of the screws that hold the metal lid with the fuel pump assembly in place and take that to the car bodywork - hey presto gauge works again !

The reason for this is the rubber gasket that insulates the lid from the rest of the car.

RedRummy · January 13, 2007, 01:23:30 AM

Really? bugger... though it would be a simple "give float a nudge and a bit of lube and hey presto"... kiinda hoped it wasn;t electrical

I took the cover off my fuel pump over Christmas ( well, the cover off the boot section)... saw a bunch of pipes and tubes and vavles and promptley put the cover back on! LOL far too scared to start messing about with all that... lol :Hammer

PETE SMITH · January 13, 2007, 01:43:52 AM

I reckon my average mileage for a full tank is around 190 miles...............now thats all sorts of driving over 8 years..........so, if you can\'t be ar*ed with the electrics, follow the mileometer and get an average!:mmmm

RedRummy · January 13, 2007, 01:53:15 AM

I been recording my mileage since I bought it, and I\'ve ranged from 16 - 18 mpg... mixture of motorway and town driving... quite often 100 mile motorway round trips.

I fill up when I reach 250Kms on the trip count... which is quite often hehe

PETE SMITH · January 13, 2007, 02:02:59 AM

250km is around 160miles.......i used google!!!!!!!.........so, if a fair bit of burning, respectable figures!:Tongue1 :yes

Initial-D · January 13, 2007, 01:02:34 PM

My gauge only goes up to 3/4 of a tank when full? Anyone got a fix please!

TwistedHumour · January 13, 2007, 02:02:44 PM

Quote from: Initial-DMy gauge only goes up to 3/4 of a tank when full? Anyone got a fix please!

Mine does exactly the same thing! I\'ve no idea what to do though

RedRummy · January 13, 2007, 03:51:06 PM

Quote from: PETE SMITH250km is around 160miles.......i used google!!!!!!!.........so, if a fair bit of burning, respectable figures!:Tongue1 :yes

I usually fill up at 250Kms, just to be safe... It has been known to run to 315Kms though... when that happens, I can get 60ltrs in there...:spank

Not good I know... I dread to think the damage running out of fuel could do to a rotary.. :2Confused :2Confused you\'d prolly have to start it by using a hypodermic needle to manually inject the fuel into the rotor housing.. :rollin

sparkgap · January 13, 2007, 11:17:34 PM

Check out my thread
http://www.mazdarotaryclub.com/forums/showthread.php?t=33518
It might be a stuck needle or capacitor plague!

sparkgap · January 13, 2007, 11:23:26 PM

Quote from: ProfThe reason for this is the rubber gasket that insulates the lid from the rest of the car.

Beg to differ, the screws fix through the lid and gasket into the tank.
The whole tank is insulated from the rest of the car by virtue of the rubber layer on the straps that hold it in place.

The only thing grounding it should be the thin wire and spade terminal which just carries current for the fuel level and "low" indicator and static discharge.
If this thin wire is faulty then grounding the tank though the bodywork as mentioned should work
The pump has its own ground return which is insulated from the tank.
Note that the terminals on the pump and the fuel sender are all bare and covered in fuel or vapour. Good job there is no oxygen in there!
Martin

Initial-D · January 14, 2007, 11:48:24 AM

Will go and have a look at the dash unit as its all out of the car at the moment, although the fact that the gauge works from empty to 3/4 would surley indicate its the sender from the fuel tank rather than the dash??

Prof · January 14, 2007, 02:15:19 PM

Quote from: sparkgapNote that the terminals on the pump and the fuel sender are all bare and covered in fuel or vapour. Good job there is no oxygen in there!
Martin

That was exactly my thoughts - but If the contacts are good there should be no sparks, and the vapour pressure of fuel in the tank will act to prevent ignition - the petrol vapour / air mixture is too rich.

sparkgap · January 14, 2007, 07:46:24 PM

Spot on Prof. Until air is let into the tank there is no chance of ignition. I reckon the most dangerous thing to do is to start fiddling with an empty tank, opening the fuel pump hole might make the perfect recipie with the vapour that is left and the air that floods in.
Because of the containment of the tank there may well be a rupture not to mention flash burns to anyone near the hole.
I\'ve experimented at work with 1m cubes of propane and air mixtures, weight for weight propane and air give out far more energy than TNT at the perfect mix. I think petrol vapour might be similar.
TNT is safer to handle because it takes more than a electrostatic spark to set it off.
What ever you do just be careful!

Martin

RedRummy · January 26, 2007, 02:07:26 PM

Quote from: sparkgapI\'ve experimented at work with 1m cubes of propane and air mixtures, weight for weight propane and air give out far more energy than TNT at the perfect mix. I think petrol vapour might be similar.
TNT is safer to handle because it takes more than a electrostatic spark to set it off.
What ever you do just be careful!

Martin

Where the hell do you work!! sounds exciting!