I just purchased an 89 Honda accord lxi and the gas gauge works when filled then drops to empty after it reaches ¾ full. What could be causing this? Normally I'd it's broken it doesn't work at all I thought. Well the low fuel light still illuminate?

 

Well, I can't help with the electrical solution, but someone else will I bet.


In meantime, reset the trip odometer at every fill-up and don't go more than 200 miles until gas fill-up
until you track your new car's mpg. Accord tanks hold ~16 gallons, so this range to refill is conservative.
e.g., my '92 can go 450 - 525 miles on the highway on a tank, winter is bit less - as is 'town driving.'
I've never gotten less than 24 mpg even in cold.


welcome to the Accord world with your new-to-you one...

 

You will need to check the dashboard gauge movement by shorting the fuel sender wire (yel/wht in 90 Accord) to ground w/ keyswitch OFF. Turn keyswitch ON and if gauge begins to immediately move towards Full, turn keyswitch OFF. Prompt movement of fuel level indicator means gauge movement is OK.

Good movement means tank sending unit needs to be replaced. This requires removal of fuel pump/sending unit assy and replacement. At least in did on 90 Accord, and may be same on 89 Accord. Only shop manual I have for 89 Accord is broken into many pieces and difficult to find fuel pump replacement. Removal of fuel pump/sending unit assy usually requires removal of fuel tank, a non-trivial exercise. It may be acceptable to live w/o a fuel gauge and use procedure suggested.

good luck

 

Just an FYI, the 3rd gens have a nice little panel in the trunk where you can get to/replace the pump and or the sending unit if need be.

Also, pretty sure the 3rd gens have a 14.5 gallon tank.

Last, I've got a pretty good 3rd gen manual. So if you have a volt meter and want to take some resistance readings from the sending unit let me know.