help with petrol gauge

[ashc]

had an embarassing episode friday morning when my car spluttered and died, and came to a stop on a dangerous bend of the dual carriageway with no hard shoulder, reminiscent of my 2006 disaster. Phoned the AA and the old bill (who never came) and eventually by pure chance a friend passed and by this point i\'d decided i might have run out of petrol (so he went and got some for me - top bloke).
The problem is, the fuel gauge light hadn\'t come on (has before!) and the needle still said it was just touching the reserve. I thought i had a few miles left....I wondered if the sock had come off the fuel pump (supra TT) or the dash bulb had blown - sock ok, and dash bulb changed - now it is on all the time. the needle seems to work fine, perhaps slightly over-reading but only by a mm. What would cause this? What makes the bulb come on - is it a sensor in the fuel pump complex or something linked to the gauge cluster / needle position? Now the light is on all the time, its annoying!!

any help, as always, appreciated. In the meantime, i\'m taking careful note of the mileage!!

[ashc]

right, the light is still on. i have emery papered all the grounds, and had the dash out all over again. Everything looks ok. There is a constant 12v to the petrol gauge dash light. The gauge itself works fine. I havent had the fuel pump out as i have a full tank of petrol. Anyone got any other bright ideas before i assume its a faulty sender and replace the fuel pump assembly?

[ashc]

of note, i found probably 2 litres of water sloshing around under the spare tyre, i have to remember to not open the boot when there are water droplets on the rear glass, they run THERE!

[Nik da Greek]

Can\'t help with the fuel light problem, dude, but your spare tyre well fishtank sounds familiar. I had this on my old Rex (assumin you\'ve got an FD?) and it was water getting in where the spoiler mounts had broken and the foam sealant stuff had perished as a result, as well as round the rear window seal. Cos the car had been kept outside, all the rubber trims were just brittle and knackered. Might be worth you investigating before your rear end rots out, as it were! Hopefully just a coincidence, water does run into the boot from the angle where it goes from flat to curved if you open it when its got rain all over it.

[ashc]

hehe! good job i didn\'t have a sub mounted there! No obvious corrosion to see at the moment, i\'ll keep a close eye on it. Regarding the petrol light, i\'m going to replace the sender and report back.....

[RedRummy]

got similar problems myself...  my gauge isn;t working, but the fuel light comes on when low...
gauge always points to empty, so I reckon the two are not connected (or both get set using the sensor in the tank (float thingy?))

[ashc]

car wouldn\'t start today after a 10min drive to the shops, phoned everyone i know & tharek suggested it might be flooded so i pulled the egi relay and cranked it a bit, then reinstalled it but still wouldn\'t start. After about 30mins, i tried it again and it did - just as the aa arrived! This evening i pulled the fuel pump assembly incase some of the wiring was dodgy or the sock had come off the pump or float stuck etc but it all looks absolutely fine. Then i pulled the dash and clocks, and got my multitester on it, chased it but cant understand why the petrol light circuit is live? i\'ve gone through the electrical wiring diagram and it only seems to go to the sensor in the tank, so i\'m confused. I think i\'ll try replacing the pump assembly, sender unit and float etc and see if that makes any difference? Otherwise it must be a short somewhere in the loom i suppose, which is a bit worrying. The only other thing of note that has happened recently was some water ingress into the spare tyre well i discovered about 3wks ago, hasn\'t happened since and it is as dry as a bone in there now. friggin electrical gremlins......well, its good to talk anyway.

[RedRummy]

what a nightmare, I feel for you mate...

must be related to the water build up... maybe the trigger for the fuel light has rusted up, so its now making contact permanently?

only a guess though.

[ashc]

pulled the plugs, pretty caked in carbon deposits (ngk bur9eqp all four) so replaced them and it really goes like stink now, starts from hot or cold fine again. But why should they need replacing after just 2500 miles, is that normal - was hoping for a bit more. could it be asymptom of running rich?
second thing, should i put 2 bur7eqps and 2 bur9eqps in as per fsm? could the colder plugs be the cause of the flooding etc? will it affect the pfc map if i change the plugs back to standard config?

[memski]

Hi mate, the plugs shouldn\'t affect the map, you should  be fine with 9s all round. Plugs are more likely to foul if you do a lot of pootling round town and short journeys, let her stretch her legs from time to time and wind the revs out to keep them (and your engine)clean.

[ashc]

Hi mate, the plugs shouldn\'t affect the map, you should  be fine with 9s all round. Plugs are more likely to foul if you do a lot of pootling round town and short journeys, let her stretch her legs from time to time and wind the revs out to keep them (and your engine)clean.

thanks! i\'ll post a pic up later of the plugs i pulled out - i\'m not sure if the carbon can be cleaned off and they can be re-used, apart from the caking (2-3mm!!) they look ok where its come off....