Erroneous gas gage.
 

O.k. I have done numerous searches on this topic on various 350z forums and found that some people also have this problem, but no solution.

I took my 03 Z in for the fuel filler line recall. So after they had finished the TSB, the Nissan service dept. filled up my tank for free The tech noticed that the gas gage was not at full, but rather a 3/4 full. So they called me and asked if I had a problem with the gage. To which I said yes. I'm now into the second week of waiting as the dealership and Nissan tech line try to finding a solution. They have changed out the sending unit, pulled the dash, installed new FID valve, and changed the wire harness connector. I'll share the solution, when Nissan finds problem.

I don't mean to change the subject on you but I just noticed something that ought to be record-setting. You've been on the board for almost four years yet just made your second post. Talk about "lurking".

Thought you were gonna talk about gas mileage. Was about to say...lol
Anyways, filled up today doing 60mph cruise control, flat road, 90 degrees (humid) and was getting 36.5 to 37.x mpg :D
This car is BADASS.

I have had the same problem. Everytime I fill up my tank it only goes to 3/4 full and no higher. My car also reads at E and will only take 15 Gallons so I know there is 1.5 gallons in the tank. I have wanted to take it in but have been out of town and I dont trust anyone enough to take it in for me. Please keep updating as to what they do so I can give the techs a little info when I go in.

Good Luck

My gas gauge only reads 3/4 regardless if the tanks is full or empty...:icon22:

Just noticed too. :icon18:

There is a TSB for the tank being hard to fill completely. The techs should be on top of that. There is a faulty shutter valve in some Z's. I think I had the problem worse than most people here, judging from other peoples posts on the problem. In the course of a year and a half I could NEVER get a full tank no matter what I did. It eventually got on my nerves and I took it in and had them fix it. The sending unit is also another common problem but I have not had any other issues with the fuel system other than the hard-to-fill problem.

i fuel up when my gas light turns on and i only get 15.5 gallons topped off to the top of the line. but my gauge goes full.... i dont know

Ya know, I was just thinking about this. I filled up yesterday, gas gauge showed roughly 1/8 of a tank (dte said 80mi.). I put in 14.9 gal. and it indicated "full". Now a little math between my trip odo and my fuel economy showed that it was spot on. So this means that there is FIVE GALLONS in that last eighth of a tank....does this strike anyone else as odd?:confused:

Mine just recently started having the problem of not reaching full. I took it in for the recall as well but don't know if that has anything to do with it. I just reset my trip meter between fill ups and that works pretty well but I'd rather have a permanent solution.

Holy sh!t.. I thought I was losing my mind...

I've filled my Z up three times so far. First time it only took 8 gallons and stopped with the gauge showing 1/2 full. The second time it took about 12 gallons and showed full. The last time, the same 8 gallons again and half full... wtf?

I guess now I have to search on this. I kinda figured that if there was a TSB on this the dealer would have fixed it before selling it to me a few weeks ago.. but that would make too much sense. =)

Tank hard to fill?
http://www.nissanhelp.com/Ownership/.../NTB05-048.htm

Yeah, the dealership did do the shutter valve TSB. It was after performing the TSB that the dealership noticed that the gage was stopping at 3/4 full. So they called me to see if I had any problems before, and that's when I told them yes. So they borescope the tank to verify that the tank was full and it was. So that where Nissan tech line got involved.

I know four years and two post. What can I say. I'm too busy enjoying the my 350z. Well except for the last week and half.

Ah yeah... I kinda misread that. So it was your sending unit. Good deal they're getting it worked out.

Get back out there and enjoy the Z :D

Here's a related question. Prior to having the fuel vapor TSB/recall work done this weekend I noticed that when my DTE went from 1 to "-- --" that I could fill my tank and get about 18 gallons in there, meaning I had a couple gallons left when I hit the -- -- flashing. No big deal just nice to know that if I am on the highway on the way home I dont have to jump right off to fill up. Question is does the recall work in any way alter this?

I was having this issue before the TSB. I just wasn't sure whether I truly had an empty tank or the tank wasn't filling up. So after Nissan changed out the shutter valve they filled the tank up. Then verified it was full, however the gage was reading just over 3/4 tank.

I did call the dealership today and they said Nissan is overnighting a new instrument cluster. So my car has had a new sending unit, new connectors, new shutter valve, and soon a new instrument cluster. I did ask if I was going to get a Nismo cluster.......they said NO.

also the vapor recovery canister can be clogged, i have had that issue with my old rsx....... and it should be warranty also....

I swear Nissan guages are weird anyway. My stepmoms Maxima would fall FAST to 1/2 tank, and then would take forever to get to 1/4. Then 1/4 would go byebye really fast.

I *think* I noticed the same in the Z, but not quite to the same extent.

well i think we have the same or similar fuel pumps as most other cars.... maybe the floats get jammed on the fuel pumps... i know that veeder-root made the first electronic gauging fuel pump.. and now they make them for gas station that hold between 4000 to 25,000 gallons.... and they are as acurate to 2 gallons....

As I said earlier I show about 3/4 of a tank when I fill up. I hit e this morning headed to work and had 447 miles from the time I filled up to the time the little light came on. So I know my problem isn't that its not getting a full tank its got to be something else.