Notices
Maintenance & Repair 350Z up keep and diagnosing/fixing problems

FIX for gas gauge fluctuations, hard to fill

Thread Tools
 
Search this Thread
 
Old 10-15-2014, 05:07 PM
  #41  
F2CMaDMaXX
New Member
iTrader: (2)
 
F2CMaDMaXX's Avatar
 
Join Date: Sep 2011
Location: Oregon from England
Posts: 1,751
Received 7 Likes on 7 Posts
Default

5 - 50 (Full to empty) Left side.

5 - 70 (Full to empty) Right side. This one has some *possible* question over the exact figures.


The important part is making sure that the numbers move smoothly across the range.
Old 10-17-2014, 06:50 PM
  #42  
CFAUVEL
New Member
 
CFAUVEL's Avatar
 
Join Date: Oct 2014
Location: Sarasota
Posts: 181
Received 18 Likes on 15 Posts
Default my ohm ranges for the two are slightly different

Originally Posted by F2CMaDMaXX
5 - 50 (Full to empty) Left side.

5 - 70 (Full to empty) Right side. This one has some *possible* question over the exact figures.


The important part is making sure that the numbers move smoothly across the range.
I went ahead and cleaned both resistors yesterday and got the following values

2.5 - 81.5 (Full to empty) Right Side - Passenger- Primary with fuel pump
1.9 - 43 (full too empty) left side - drivers - secondary no pump

The gauge started reading just above half, where it was reading at half before. After driving 134 miles it is reading slightly less than half.
Old 10-17-2014, 07:02 PM
  #43  
F2CMaDMaXX
New Member
iTrader: (2)
 
F2CMaDMaXX's Avatar
 
Join Date: Sep 2011
Location: Oregon from England
Posts: 1,751
Received 7 Likes on 7 Posts
Default

So i'm guessing that it's why yours isn't reading right. How smooth was the progression?
Old 10-21-2014, 07:21 PM
  #44  
CFAUVEL
New Member
 
CFAUVEL's Avatar
 
Join Date: Oct 2014
Location: Sarasota
Posts: 181
Received 18 Likes on 15 Posts
Default The progression of the resistance was smooth.

Originally Posted by F2CMaDMaXX
So i'm guessing that it's why yours isn't reading right. How smooth was the progression?
Those numbers were AFTER I cleaned them though.


The gauge is acting better. Will know for sure this week when I fill up. I am over 300 miles traveled with about 114 miles being displayed as DTE. My in car calculator says I'm averaging 24 miles to the gallon, so I would expect to see at least 12 gallons to fill it up. Assuming I went the final 114 miles that should be another 4.75 gallons used, so 16.75 gallons to fill up and to go 414 miles. Right now it is reading just slightly above a quarter tank.

I think the reserve is something like 2.5 gallons right?
Old 10-23-2014, 05:32 PM
  #45  
F2CMaDMaXX
New Member
iTrader: (2)
 
F2CMaDMaXX's Avatar
 
Join Date: Sep 2011
Location: Oregon from England
Posts: 1,751
Received 7 Likes on 7 Posts
Default

Doesn't really matter if it was before or after, cleaning isn't necessarily successful.

When i next pull mine, i'm going to use 1000grit on them.

Reserve/fuel light comes on at 50 calculated miles to go, which will obviously change based on your MPG at the time. At about 24 to the gallon, you'll get clear of 430+ before needing to fill up. I always get about 18 gallons used at around 420 miles and high 23's to the gallon.
Old 10-24-2014, 04:55 AM
  #46  
CFAUVEL
New Member
 
CFAUVEL's Avatar
 
Join Date: Oct 2014
Location: Sarasota
Posts: 181
Received 18 Likes on 15 Posts
Default

"When i next pull mine, i'm going to use 1000grit on them." Exactly what I did.

Filled up yesterday and it took 15 gallons, with 60 MILES DTE, so may be still a little off, or the result of cleaning the contacts with fuel still in the tank. I'm just glad I don't have a "hard to fill" issue.

The fuel gauge needle is sitting just above F, before it was at 7/8 full.

Not trusting the gauge all that much, just looking at miles traveled as my gauge.
Old 10-26-2014, 08:10 AM
  #47  
92K1500
Registered User
iTrader: (1)
 
92K1500's Avatar
 
Join Date: Jan 2010
Location: Sapulpa, OK
Posts: 1,458
Likes: 0
Received 14 Likes on 13 Posts
Default

Originally Posted by CFAUVEL
Not trusting the gauge all that much, just looking at miles traveled as my gauge.
I do the same. I know to fill up around 380-400 daily driving. I would just like the gauge to work so it doesn't say I'm out with 0 miles left at 180-200 miles.
Old 10-26-2014, 08:30 PM
  #48  
johnx818
New Member
iTrader: (2)
 
johnx818's Avatar
 
Join Date: Apr 2013
Location: Los Angeles
Posts: 141
Received 6 Likes on 5 Posts
Default

I ended up replacing my passenger side (fuel pump side) fuel sender unit after cleaning it multiple times with little to no results. I used to think the sender unit only comes with the fuel pump so I never got around to replacing it. A call to Nissan cleared that up. Now my gauge reads like it should.

Last edited by johnx818; 10-26-2014 at 08:30 PM. Reason: Typo
Old 10-27-2014, 04:08 PM
  #49  
CFAUVEL
New Member
 
CFAUVEL's Avatar
 
Join Date: Oct 2014
Location: Sarasota
Posts: 181
Received 18 Likes on 15 Posts
Default Good news

Originally Posted by johnx818
I ended up replacing my passenger side (fuel pump side) fuel sender unit after cleaning it multiple times with little to no results. I used to think the sender unit only comes with the fuel pump so I never got around to replacing it. A call to Nissan cleared that up. Now my gauge reads like it should.
what was the part number and how much?
Old 11-17-2014, 11:42 AM
  #50  
johnx818
New Member
iTrader: (2)
 
johnx818's Avatar
 
Join Date: Apr 2013
Location: Los Angeles
Posts: 141
Received 6 Likes on 5 Posts
Default

Originally Posted by CFAUVEL
what was the part number and how much?
parts.nissanusa.com
part code: 25060Y
online price $97 and some change
this was for a 2003, if that matters.
Old 04-08-2015, 04:07 PM
  #51  
pvdao
Registered User
 
pvdao's Avatar
 
Join Date: Oct 2014
Location: New Jersey
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

Hi, I have a 2005 Z and was told (by autozone) that I need a new fuel tank pressure sensor. It looks like this (below). My question is, where is this sensor located? I assume it's somewhere near the gas tank right? I've also searched all over google and this forum, and no success.

Thanks

Amazon.com: Wells SU6854 Fuel Tank Pressure Sensor: Automotive Amazon.com: Wells SU6854 Fuel Tank Pressure Sensor: Automotive
Old 11-05-2017, 06:35 AM
  #52  
IslandHopper
Registered User
 
IslandHopper's Avatar
 
Join Date: Oct 2017
Location: NJ
Posts: 3
Received 0 Likes on 0 Posts
Default

Wow, huge thanks to this site and this write up! Followed Moses' step by steps on the G35 site (with super helpful pics) and fixed the wonky issue! Only one skinned knuckle and 45 minutes later, both sensors were pulled, cleaned, reinstalled, and the gas gauge and DTE figures are right where they should be.

Massive gratitude!
Old 11-12-2017, 06:03 AM
  #53  
agent17
Registered User
 
agent17's Avatar
 
Join Date: Nov 2017
Location: waterloo
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

I have the same issue, fully filled up with 3/4 full showing on the fuel gauge. I followed the cleaning method, worked for a week and went back how it was. Eventually I replaced both fuel sending unit with new ones but getting no results(shocked, surprised and disappointed). Anyone could advise?
Old 11-13-2017, 01:54 PM
  #54  
zakmartin
New Member
 
zakmartin's Avatar
 
Join Date: Feb 2009
Location: Seattle, WA
Posts: 2,822
Received 512 Likes on 377 Posts
Default

Are you sure you're getting a full tank of gas in there when you fill up? Our tanks hold 20 gallons, but sometimes, the vapor vent tube will turn off the filler at the pump well before the tank is full.

https://my350z.com/forum/2003-2009-n...extension.html

Also, did you go with aftermarket or OEM sending units?
Old 11-13-2017, 01:58 PM
  #55  
agent17
Registered User
 
agent17's Avatar
 
Join Date: Nov 2017
Location: waterloo
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

I am surebthe tank is full and both of then sending units are oem new
Old 11-13-2017, 02:39 PM
  #56  
zakmartin
New Member
 
zakmartin's Avatar
 
Join Date: Feb 2009
Location: Seattle, WA
Posts: 2,822
Received 512 Likes on 377 Posts
Default

I know it's a pain, but you could check the resistance readings on the OEM senders on a bench and compare them to the spec ranges outlined in the FSM on the full sweep from empty position to full position. It could also be that one of the senders is getting hung up on its mount.
Old 11-14-2017, 12:49 AM
  #57  
agent17
Registered User
 
agent17's Avatar
 
Join Date: Nov 2017
Location: waterloo
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

May I know where (which chapter?) I could find the spec resistance readings range of the fuel sending unit? Also, was it like left side measuring the first half( 1/2 to full) of the tank while right side measure the second half (empty to 1/2 )of the tank?
Old 11-14-2017, 09:32 AM
  #58  
zakmartin
New Member
 
zakmartin's Avatar
 
Join Date: Feb 2009
Location: Seattle, WA
Posts: 2,822
Received 512 Likes on 377 Posts
Default

What's the model year and trim on your Z?
Old 11-14-2017, 10:56 AM
  #59  
zakmartin
New Member
 
zakmartin's Avatar
 
Join Date: Feb 2009
Location: Seattle, WA
Posts: 2,822
Received 512 Likes on 377 Posts
Default

For future posts where you ask for help with your car, always include year, trim, mileage and mods. It'll get you a faster response every time.

So rather than go back and forth on this one, here's a sample of the information that's available in the FSM for a 2006 Coupe (this info may vary from year to year, so be sure to pull the correct FSM for your application.) To find your FSM, check the sticky thread in the Maintenance Forum with the corrected link I added on page 2. This is from the DI section (for Driver Information System) under "Fuel Level Sensor Signal Inspection"

Again, these are the resistance readings you'd get off a 2006 coupe with a properly functioning fuel level sensor.

Fuel gauge indication Value on monitor [lit.]
Full Approx. 74
Three quarters Approx. 61
Half Approx. 42
A quarter Approx. 22
Empty Approx. 8
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Uriyo_
Exterior & Interior
22
09-08-2021 08:46 AM
Colombo
Forced Induction
35
11-09-2020 10:27 AM
Tonyz_2004_350z
South East Marketplace
1
10-04-2015 12:53 PM
350z82
Exterior & Interior
19
10-01-2015 06:25 PM



Quick Reply: FIX for gas gauge fluctuations, hard to fill



All times are GMT -8. The time now is 08:52 PM.