To make sure I don't run out of gas (which I have done in the past) once the fuel gauge hits the E and the fuel light goes on I immediately find a gas station to fill up. However, I noticed that the max amount to fill is an average of 12-13 gallons (I looked at my receipts for this year). The Nissan Dealer (Hillsboro, Oregon) states that the Z has a reserve tank of 3-4 gallons, and some of the posts here confirm that but I can't find this spec in the service manual.

I'm trying to figure out if this is normal or if there may be an underlying issue. Per my VIN I am not part of the fuel filler line recall and the fuel guage does reach the top once the tank is full. 13 gallons (new gas) + 4 gallons (reserve)=17 which is still 3 gallons from max capacity of 20. I average 375 total miles driven (mixed surface/highway ~29 mpg) once the fuel guage touches E and the light goes on and I never top off. I want to figure this out and am almost to the point of bringing a 1 gallon portable tank and driving it to empty!

Any insight to what might be happening?

Thanks much!

 

The tank has a 20 gallon capacity. When the fuel guage reads empty and the digital readout shows 0 miles till empty, you still have 3 gallons to go.

 

Not sure about the "reserve tank" but what camaro is saying sounds about right. I've driven for about 50 miles while the DTE read "----".

I can squeeze in about 17 gallons or so if I fill up from E.

 

Your curiosity served you correctly.

Our Z's have several known issues with the fuel system(not including the recall you mentioned). One problem is that the tanks won't fill completely before the pump shuts off, which is due to a faulty shutter valve. Another problem is that the sending unit does not report the fuel level accurately. These two problems compounded could make diagnosing the problem, by just keeping track of numbers, difficult.

Our tanks are 20 gallons, and if everything is working the way it should(full tank, getting accurate readings from the sending unit), when driving consistantly and the DTE meter says you're empty, you still have 3 gallons of gas left. I've tested this out on mine.... I will drive as consistant as possible... right as soon as it says I'm "empty" I stop to get gas. 17 gallons almost perfectly.

 

I just fill up at 1/8 tank or so and never worry about having to rely on the reserve and possibly running out of gas...

 

+1 on what roast said.. I get about 400 miles from full to empty (on the dashboard gauge). When I fill up, it's about 16-17 gallons.

 

Thanks for the reply.

If the tank fills completely (reaches max on fuel guage), then it seems the likely issue may be the sending unit which seems to make sense.

If the fuel "sending unit" is the same as the fuel "sensor unit" in the service manual it doesn't seem like a 1 hour job....argh

Is there is a TSB specifically addressing repair/replace for the sending/sensor unit?

Thanks!

 

good to know, i'm in the ball park at 375 miles.

 

You guys know that vertical pedal on the right is the throttle, right? I usually get around 300.

 

I get about 400 miles from F to E.. and that's with me redlining 3rd and 4th gear on the highway pretty often.

 

did you always fill up at around 13-14 gallons during your break in period or after that? if so, your car's computer might have learned/adapted your behavior in filling up at a certain point and thus setting off alert when you normally like to fill up...next time when your car is on E, drive it until it shows "---" and don't fill up until 30-50 miles after that....do that for awhile and see how your reading wiill change...

 

I supposed that's what I get for modding my car and driving it like I stole it. Good thing I have a Chevron card.

 

Mine will read E and let me pump in about 16.8 gallons.

Running it much lower than that runs the risk of shortening the fuel pump life.

Chris

 

i also try not to put a stress on the fuel pump so hitting the pump slightly before the E might be a factor...i'm gonna run it to empty to get to the bottom of this (bad pun).

 

I think I always filled up whenever the guage hit E or was near it. I pulled gas receipts for the last couple years. The first year (2004) I averaged pumping 16 gallons with a max fill of 17 gallons. 2005 I averaged about 15 gallons with a max fill of 17.45 gallons. This year I'm averaging 13 gal with a max fill of 13.9 gal. It seems like the avg fill is decreasing....maybe I'm just being more conservative. I'm going to start driving it after the "---" a couple times and see what changes. Thanks.

 

keep us posted and let us know how that goes...

 

check this out everyone.

I decided to take the gauge past the "---" for some miles and see what happens. Once I got the DTE to 35 miles left to empty the DTE started climbing from 35 to as high as 85 DTE within 15-20 minutes driving 30 mph on surface streets. It finally stabilized at 85 DTE and slowly creeped lower at a reasonable rate. My theory is that the fuel sensor was somehow reset by taking the tank much lower than it usually goes. I drove it about 9 miles after it hit "---" to reach 398 miles and *only* pumped in 15.6 gallons which is 2 gallons more than I usually do. I'm going to continue this a couple more times. I decided I'm not going to drive it completely bc I don't wanna damage the fuel pump. The next question......has ANYONE been able to fill past 17 gallons? time for a new thread....

 

Running low on fuel will NOT damage the fuel pump.

1) As long as there is any fuel, it provides cooling for the pump.

2) The dirt and condensate in the feul tank is ALWAYS at the bottom.

 

I usually fill-up when DTE reads 0, and it takes 18.5-18.7 gallons. Seems like my 'reserve' tank is smaller than most here.

 

Sorry to revive this old post.. but i have the same problem.. for those that say you dont' have the issue.. you need to drive it on the highway from 1/2 to 1/4 and you'll see the same symptons as the oringal post.. i took it past it and completely ran out of fuel.. filled her up.. only 14 gallons.. 14.... This was only on highway.. this has happened twice.. where my fuel gauge would drop from a little over 1/4 to empty right away.

On street my car is fine.. it seems to have something to do with a constant g force put on the fuel.. any recalls on this?