'90 240 inacurate fuel gauge

[pmkls2]

I have noticed that my fuel gauge is getting more and more inacurate every day. It seems to drop down faster and show less fuel than before. For a while I was thinking that I was getting less gas mileage so I really started keeping an eye on things and I noticed that my mileage is staying the same but my gauge is reading lower than before making me think I need gas. Last night I went to go get gas because my tank was showing almost empty and it only took 11.3 gallons. Usually I put in about 13.5 gallons when the gauge gets to this point. The wierd part is that it doesnt do it every tankfull, but it is getting more and more consistent now. I work on GM cars for a living and almost all of them have similar problems with the sending unit in the tank, but when they go bad they show more fuel than actual rather than less (this could be just that they are wired different). So am I on the right track here thinking that my fuel level sensor might be the cause? Because in my field I have never seen a bad I/P cluster do this and that is pretty much the whole system less wiring, but I dont work on nissans. Any suggestions here are very welcome,

Phil

[navysnail]

id have to say that the sending unit is bad. ill get out my fsm and check to see if it increases or decreases with fuel level going down.

[pmkls2]

Thanks that would be great. I am sure that is my problem and I will probably try to clean it. There is a good chance that corrosion is the cause so I may be able to clean the contacts and put off buying a sender for a while (I already spent $400 on the car last week).

[navysnail]

i have also heard of holes in the floats sometimes, just sumthing to think abouthttp://www.240sx.org/faq/index.html

[pmkls2]

Thanks for the info. I will definately check that out.I sometimes forget the general rule about checking the simple things first.