HELP - Fuel Gauge issues

370z1

Has anybody installed an aftermarket Fuel Level Gauge? I am interested in doing this to ad to my other after market gauges I have installed but am having trouble finding the Resistance values to my 2011 370Z Sender unit(s) in order to purchase the correct gauge, ie: (? Ohms = Empty) & (? Ohms = Full). Also I am a little unsure since we have two tanks one behind each seat but am guessing their configuration is a Primary Tank and Secondary Tank whereas all readings come from the primary tank as the secondary tank feeds the primary tank by a vacuum line so its function is like a reservoir and the existing digital (The DOTS) fuel level gauge takes the average from both sensors from the primary tank only (I believe)?

I searched the web and looked here for any DIY Fuel Level Gauge installation threads that would help but can't seem to find these answers so any help would be greatly appreciated...

2. Which Sending Unit do I connect the after market Fuel Level Gauge to?
3. Where should I tap into the sensor for the gauge wires?
3. What Resistance (Ohm) values do I use when purchasing the NEW Fuel Level Gauge ie: "? Ohms = EMPTY" and "? Ohms = FULL"?

I own a 2011 370Z with Sports Package (Stick) with the Stillen SuperCharger.

Thank you guys in advance if you can help point me in the right direction. If you want to see the gauges I have installed already have a look at my photo album i there should be some pic in there.

Thank you again for your help.....

My factory gauge works fine just want a different style of gauge so IF I can tap off the PCB behind the Instrument Panel I am ok with that but figured that won't work since the analog data has already been converted to digital so I believe I will need to pull off the sender sensor directly just don't know the resistance values nor where the access point is?

Rusty

Your idea of our fuel tank is screwed up. We have a saddle tank. Its one tank with a hump in the middle for driveshaft clearance. There is a fuel level sender on each side of the tank. The gauge takes both readings to give you a level reading on the gauge. The person to talk to is phunk. He's the fuel system SME. Here's a link to my thread on installing phunk's roadrace fuel pump. It has pictures of the inside of the fuel tank.

phunk's road race fuel pump install

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370z1

Hey Rusty, your "Saddle Tank" description would have been plenty to get my head around it my friend... I did say I was "Unsure" and that I was "guessing" but hey, crack a cold one on me....I do appreciate the link to YOUR other post about the Fuel Pump and the Sponsor
[Phunk's] contact info. I read your entire post and if or when I need to replace the fuel pump I know where to look. I found the information I was asking about and have shared here for others who might be looking. Since there isn't any info (prior to 09/26/17) out there
on what resistance values = EMPTY or FULL that are Factory Sender is using or which sender we need to tap into ie: saddle bag sensor on the Passenger's side or saddle bag sensor on the Drivers's side as both use diffeerent resistance values (see below the OHM's for EACH
Fuel Level SENSOR. Based on the data below believe I have all the information needed to install an After Market Fuel Gauge. Even though i have the OHM's at Emptyt and at Full I am going with a "Programable" Fuel Level Gauge which is like a pot, which allows us to change
the input resistance of the gauge wires to match the Ohms of the sender and get an accurate Empty and Full reading. Hopefully this helps anybody looking to install a Fuel Level Gauge. After I get done wwith my installation I will create a DIY guide to validate the Gauge I
purcchased worked, and that the "MAIN" sensor I tap off of also worked as oppossed to the "SUB Senseor" (which is what [last week me] would have called the sensor on Tank 2).


MAIN (Fuel Level Sensor Unit) (Driver Side Saddle) (Right side of car when facing windshield from front bumper)
Terminals: 2 & 5
Condition: Full = 3 Ohm's (Approx) (Float Height: 229.7mm / 9.04in)
Condition: Empty = 80 Ohms (Approx) (Float Height: 38.5mm / 1.52in)

SUB (Fuel Level Sensor Unit) (Passenger Side Saddle) (Left side of car when facing windshield from front bumper)
Terminals: 1 & 2
Condition: Full = 3 Ohm's (Approx) (Float Height: 32.8mm / 1.29in)
Condition: Empty = 40.9 Ohms (Approx) (Float Height: 241.1mm / 9.49in)



Picture 1 - Shows Locations of both MAIN fuel level sensor and SUB fuel level sensor






Picture 2 - Lists Locations of both sensors and other procedures.






Picture 3 - 3D View / exploded view of Tank and connections






Picture 4 - Lists both Fuel Level Sensors and their Resistances in (Ohms) at conditional states such as Empty and /or Full







Picture 5 - 3D View / exploded view of Fuel Level Sensor(s), Fuel Filter and Fuel Pump Assembly







All information except for the aftermarket gauge was sourced from our 370Z 2011 Service Manual and I have attached the PDF sections relivent to a DIY Fuel Level Gauge installation.


Next Post to follow will be notes on how my install went and the steps I took for a better (play by play) on what to expect, and pictures of the completed Fuel Level Gauge Installation. Once I complete that I will update this post but point
a URL redirect to a DIY new Thread i will start, if somebody doesn't beat me to it?

Thanks in advance for any help you shed on this topic....

I tried uploading the PDF Service Manual called, SECTION MWI AMETER, WARNING LAMP & INDICATOR but it was 1.66MB and the limit is 1.0MB so you will need to get this one yourself, just search on Service Manual.


PS: You MUST BE logged in to the Forum to SEE Inserted Pictures. Attachments can be downloaded by anyone but inserted images can only be seen by logged in users of this forum.

Attached Files

Fuel System.pdf (494.4 KB, 83 views)

Rusty

Good job! You did a chit load of digging for this. Which after market gauge you installing? Gave you some reps too.

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浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
http://www.the370z.com/members-370z-...o-journal.html

dedoom

Has the issue always been caused by the fuel baskets sensor? I read for the 2009 MY there was a persistent issue for the fuel basket.

Z's

My 09 had the basket fall off into the tank as well. Not very uncommon from what I've read over the years. It happens on other Nissan models as far as I'm aware. All the symptoms everyone had sounded like a broken pump housing to me.

1slow370

you know a lot of the time you can pull out the sending units and on the arm is a little sweeping contact that rubs against a potentiometer strip on the sensor cleaning that with some alcohol can fix it if it is just covered in deposits. if its worn through its bad. also sometimes you can bend the little contact to put more pressure on the strip. saves replacing $x00 sending units

see here

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