The gas gauge on my 92 Dodge Grand Caravan stopped working over the past two days. Two days ago it seemed to be fine. Yesterday it indicated that I had a quarter tank when it should have been 3/4 like the day before. The car hasn't been driven more than 30 miles in the past few days. This morning it went from 1/8 to empty in a few miles (the need gas warning light also came on). I added about 4 gallons of fuel and there was no movement in the gas gauge - it still reads empty and the low fuel warning light is on. Any suggestions on a repair would be appreciated - I have a 500 mile trip at the end of the week.

my 1992 does pretty much the same thing usually i can fil it up and it wiill say 3/4 tops and stay that way for about 60-70 miles then drops to half a tank stays there for another 40 miles then empty and back up to 1/4 and then it says empty and a mile later its back up to 3/8 and more occasionally , on average Im only spending 30-40 bucks to fill it up @3.50 a a gallon and average about 150 miles a tank , it seems to run GREAT other than popping out of drive sometimes and only once did I actally have to spend 48 to fill up when gas had dropped another 30cents a gallon Im confused since theres no leaks missing or smoke ? my 1992 does pretty much the same thing usually i can fil it up and it wiill say 3/4 tops and stay that way for about 60-70 miles then drops to half a tank stays there for another 40 miles then empty and back up to 1/4 and then it says empty and a mile later its back up to 3/8 and more occasionally , on average Im only spending 30-40 bucks to fill it up @3.50 a a gallon and average about 150 miles a tank , it seems to run GREAT other than popping out of drive sometimes and only once did I actally have to spend 48 to fill up when gas had dropped another 30cents a gallon Im confused since theres no leaks missing or smoke ?