How to - Fix the Inaccurate Fuel Gauge (.pdf)

[DoubleU]

Steve,

 

Fantastic guide, I did the job yesterday and could NOT have done it without your help. Amazing! Big thanks.

 

My tank was saying empty but when I opened up there was loads of fuel and now I've cleaned both senders it's saying just over a quarter of a tank.

I may yet need a new sender on the fuel pump (drivers side) as the resistance on that was less linear than the passenger side. No fear in tackling that job now though.

 

Just one thing - It was all too easy to drop the 6 little screws holding the tank cap on. Especially on the drivers side where it's under a bit of spring pressure from the fuel pump.

I lost one and had to appeal for a spare on the forum today as it disappeared into the belly of the car somewhere and didn't drop out.

Be warned all you butterfingers!

 

Thanks to ZmanAlex for coming to my rescue - and for supplying the new O-rings for the job in the first place.

[SteveW]

Pesky little bloody screws!!!

[AG350z]

Looks like this could be the ticket! 5 months ago my 04 plate started playing up, I couldn't get the tank above 3/4 full…however today the dte went from 75 to 18 to -----dte in about 8 miles and has remained this way. I found sometimes taking the cap off the filler did something but can't ignore it anymore . Thanks for the excellent guide!

[japcarsbrett]

Used this guide it worked a treat thank you very much SteveW top man

 

As to what some have asked about depressurizing the fuel tank mine had half a tank but i had no idea as before i did this it showed the warning light and no fuel so i had to guess and when i fixed it i had half a tank!

 

Anyway what i did was i left the fuel cap undone and i left the car over night for it to depressurize by itself and didn't turn the car on or even turn the keys in the ignition else it will pump the fuel into the system so i left the car over night with the fuel cap undone and did this and had no fuel come out of the pipes and as i said i even had half a tank!

[edwmas]

Guys,

So I did this at a local mechanic. The sensor straight away was working well until I filled up again. The sensor now is not moving at all with a full tank :S. I also noticed that when I filled the tank there was a small leak.

 

Could it be that there is a leak with the O rings and this is effecting the pressure inside the tank and therefore the fuel sensor?

 

Would appreciate any advice.

 

Thanks

edwmas

[c0vert]

Excellent guide. I'll save it for later in case it's needed. As a way of saving time on it however, I have two suggestions. Am I correct in assuming that it seems more likely that the driver side fuel sender (behind the subwoofer where the fuel pump is) is the one likely to be getting dirty? And secondly, I accidentally fixed my dodgy gauge with the following method:

 

When I bought the car in February this year (2004 350Z) I filled it up and the gauge would only read 3/4 of a tank, and it was like that consistently. Now as a habit, I always when buying a new car, put in a few treatments of RedX petrol additive (it's supposed to clean the injectors and such, but a lot of people believe it's pointless stuff). Anyway I eventually did it (when I saw redX on offer in Costco, 4 big bottles for like £12) and after the third treatment and full tank of fuel, the gauge now reads properly that I have a full tank. And there you have it. If it can clean the fuel injectors, then it can clean the fuel tank senders too.

Give it a go

[SteveW]

Good shout, it's worth a try saves you stripping it all. I might have to give it a go as mine is all over the place again. Which Redex did you use?

[SteveW]

I am also trailing the Redex fuel treatment fix. After 1 treatment the gauge does appear more accurate but not yet correct. I will feedback progress as the trial continues.

[RobPhoboS]

I am also trailing the Redex fuel treatment fix. After 1 treatment the gauge does appear more accurate but not yet correct. I will feedback progress as the trial continues.

 

I tried a can of BG44k (awful design, need a funnel!) - I may try another but what's happening for me is when it's full it reads fairly accurately but once down to halfway, it goes a bit mad. So one of the sensors is definitely buggered

[glrnet]

I am also trailing the Redex fuel treatment fix. After 1 treatment the gauge does appear more accurate but not yet correct. I will feedback progress as the trial continues.

 

I tried a can of BG44k (awful design, need a funnel!) - I may try another but what's happening for me is when it's full it reads fairly accurately but once down to halfway, it goes a bit mad. So one of the sensors is definitely buggered

Same here Rob, fixed it once and now it's gone crazy again, DTE showing nothing but Scanguage showing 163 miles to empty, I just rely on Scanguage now, it's always pretty spot on, if it says 2 gallons to empty it's usual almost spot on.

[Adrian@TORQEN]

Time to source some new OEM fuel buckets for you guys

[HiddenWomble]

My fuel gage has never gone up to full since getting her a month ago. This fix was on the list of bits and bobs that need to be sorted but I thought I'd give the fuel cleaner a go. I picked up the 4 pack box for a tenner at halfords and filled my tank before the car was due to sit idle for a few days. It didn't rise to the top over that time but where it would give the low fuel light when at 1/4 tank this time it got all the way to the red line before the light came on. Got 380 miles out of that tank

 

When I filled up it shot right up to the top. I expect it still isn't quite there yet but that was only after one tank's worth of treatment. The 2nd treatment is already in and depending on how that goes I might do more or leave it as is. Will be interesting to see how long it lasts.

[HiddenWomble]

Didn't last as long as I'd hoped, put the 3rd shot in but haven't been able to find a few days for her to sit yet so that didn't really help. Might look into a more permanent fix but it was great to get the fuel gauge working properly even for a while so I could learn how far I can get on one tank. Now I don't panic as much when the fuel gauge goes mad for the last quarter.

[Adrian@TORQEN]

New fuel bucket assembly would be the solution, but is not cheap.

 

[nissanman312]

I had feul sender replacement by nissan sorted it for about a week then broke again

[SteveW]

Did they replace the sender in the passenger side of the tank or the fuel pump and sender from the driver side of the tank?

[mikewoodhouse]

Thanks for a great guide. just one point though; does the sender float arm go to the center of the tank or the outside wall?

[mx49]

Has anyone still got the PDF of how to do this as my fuel gauge is playing up and when I click on the original link I get a bad address report :-(

 

Cheers

[MDMetal]

I don't have the pdf but I have done the procedure, it's not too complex,

 

-Move your seats forward

-Disconnect the battery

-remove the subwoofer/parcel shift trim

-Remove the insulation/sound deadening behind.

-Remove the screws from the tops of each side tank

-remove the o rings,

-wiggle the sender out.

-Clean/replace

-reassemble

 

Make sure to do it outside or in an open space, with as little fuel in the tank as possible as you'll be getting lots of fumes.

Advice at the time was to replace the o rings and avoid getting fuel on them.

Electrical contact cleaner was what I used to clean the floats.

 

Bare in mind it'll break again but maybe not quite as badly as it was previously, mine still gets fluffy once you get under 70 miles

 

 

[Kryptek49]

54 minutes ago, mx49 said:

Has anyone still got the PDF of how to do this as my fuel gauge is playing up and when I click on the original link I get a bad address report :-(

 

Cheers

PDF still works fine for me, I've uploaded it for you again here

Fixing the FuelGauge.pdf

[mx49]

Cheers Kryptek :-)