nh7cy

So my gas guage has been bouncing around alot lately. When I fill up the tank the gas guage only goes up to three quarters then proceeds to bounce between three quarters and half a tank. After about two days of moderate driving (maybe 60-80 miles a day TOPS) my gas guage will start bouncing between empty and a quarter tank. After two days my tank shouldn't be anywhere near empty, my truck which gets about 15 miles per gallon doesn't even go through this much gas.

Any ideas?

FRporscheman

1. Smack the dash / gauge to see if that effects the bouncing. Check the electrical connector to the gauge, especially if the smacking had an effect.

2. Remove the rear carpet and use a multimeter on the contacts for the fuel level sender to see if it still works. I think clarks-garage has the info on that.

Lord_Galva

I was wondering about that aswell. My gas guage only goes to 3/4 never to full.

tomrc

I cleaned all my connectors at the sender under the rear carpet, particularly the ground. Works like a champ.

MomentumGuy

When you fill up at the gas station, how much do you put in?

I put in 15 gallons when my gauge reads what I would be comfortable with as empty (actually below 1/4 on the gauge - mine doesn't seem to have the correct "range" either). I also usually get about 300 miles per tank.

If you can't put in 12-15 gallons, then I would say it is the fuel sender. If you put in the full amount, then you might want to look elsewhere.

Hope this helps...

nh7cy

i put in about 12 gallons from what im guessing but i'll check that fuel sender, thanks for the suggestions!

FRporscheman

I know why the gauges never read full range. It's really hard to explain... basically take out your fuel level sender and look really closely at the float and the two wires. Make sure the wires are straight, and that the metal wiper arms that touch the wires are not worn out or eaten through.

My old first 944 had problems where the gauge would never go below 1/4. I refurbished the wiper arms on the float, and it fixed the problem. The gauge would read all the way to E and turn on the warning light.

YMMV.

Lord_Galva

Tried to get to the sender today and I broke something. One of the wires going to the sender. Gaaaa! Not the wire itself but the copper piece connected to it. And now I have to go to work! I'm prayin nothing bad will happen.

billthe3

I hope you've figured out what your average mpg is on previous tanks. As long as you have, just watch the mileage and get gas whenever you use about 17ga worth of gas.

nh7cy

thats what i've been doing, i haven't gotten around to checking it out yet as i've been busy all day but i figure filling up once the needle starts bouncing around empty brings about the good habit of filling up at quarter tank which is probably whats left when the guage reads E..

Mike C.

As long as you odometer works you don't need a gas gage. Just write down the mileage when you fill up, then drive for 200 miles (to be safe) and fill it again. The number of gallons it took to fill the second time was the amount used to go however many miles you drove since writing down the original mileage. This number of miles divided by the gas it took to fill upagain will give you a rough idea on you gas mileage (in miles per gallon). City driving it should be no lower than 18-19, highway 24-25. Once you do this a few times you'll get a better idea what your typical gas mileage is and then you can use your trip odometer to set zero everytime you fill up. Then you re-fill at 300 miles or whatever your mpg dictates.

billthe3

No need to write mileage numbers down - thats what the trip odo is for.


But yeah, knowing your average mpg on highway and around town is great knowledge. I've figured out that in my camry the very iffy gas light will start to flicker on when I still have 4 gallons left, so I am still able to drive a good 50mi and still be safe before I have to fill up.

nh7cy

thats what i usually do with my truck. i'll have to get back to resetting the odometer whenever i fill up though, last time i forgot and didn't want to reset it until next time i fill up or else i'll have an inaccurate average.

UncleMaz

You can clean your sender with some brake cleaner (that is if you haven't f' it up too much). The float gets varnished and motion/range suffer or just get a new sender (they're spensive).

UncleMaz

Also, ground your lead and watch if the gauge pegs. If the gauge pegs, it is most likely your sender.