Fuel Tank/Gauge Question

[kpaaaav]

When I first bought my 11' FX35, I could drive about 140-160 miles (depending on hwy/street and the way i drove) before the fuel gauge even reached 3/4 tank from full. I was driving about 350-400 miles (again depending on how i was driving and where) before the gauge reached 1/4 tank. When the gauge showed that I have 0 miles to go, I could fill up for about 22-23 gallons (depending on how much I drive)

My car recently had problems with the fuel sending units. Even with the gas full, my gauge would show 0 gas and the low fuel light would remain on. I took it to the dealer and they replaced the fuel sending units. Then the problem happened again and i took it back to the dealing and they said they had to calibrate the fuel sending units. Then the problem happened yet again, took it back to the dealer and they replaced the fuel sending units again.

After the second time they replaced the sending units, my gauge shows completely different now. There is sporadic movement with the gauge and now, i can barely drive 100 miles when the gauge reaches 3/4 tank and at about 280 miles its already at 1/4 tank. Now when the gauge shows 0 miles and i go to fill up, i can barely fill up 20 gallons, maybe 21 depending on how long i drive the car after it shows 0 gas.

Now i don't know what is normal behavior here for my car. Was the reading that I was getting before correct, or are the readings that I am getting now correct? There is such a big difference that I just don't know. I thought it was a little odd my car was able to go the mileage that it did before, but hey I thought that was awesome. Now that it shows it is going a lot less, it kind of sucks, but I wanted to get your thoughts on what is correct. Were the readings I was getting before more accurate or are the readings I am getting now more accurate?

Thanks for the help.

 

[MTN FX]

I would keep a fuel log for a while writing down the mileage and amount of fuel when filling and manually track your fuel consumption.This will give you a baseline to compare to what you are seeing to actual usage. Then if you see a discrepancy you will have verified info to go back to dealer with.

---------- Post added at 09:49 AM ---------- Previous post was at 09:43 AM ----------

There are some good apps like Gas Cubby that are free to download to your phone that can track this info for you.

 

[la_fx35]

Hmm, interesting to hear that the same problem on a 2nd Gen. The first Gen has the same problem. There are two compartments to the gas tank, the fuel pump is on the passenger rear with a level sensor and there is another level sensor (sending unit) on the driver rear. From your post, it seems to me that they replace the sending unit (driver side) twice and not the fuel pump. Nothing wrong with the fuel pump, but the level senor and the fuel pump is one unit, you cannot replace just the level sensor that is on the fuel pump.

It will be interesting to see how much gas is really in the tank if you don't mind doing a little exploration yourself. Here is the DIY on the 1st Gen. https://www.infinitiscene.com/search/1/?q=13056-Gas-Gauge-Level-Fix
Not asking you to do the DIY, but to open the tank and see it there is a huge gas level differences between the two compartments. Be careful, there will be gas fume once you open up the gas tank and may cause a fire with open flame around you. No need to disconnect the gas line, just take apart whats needed so you can look into the tank to check the gas level on each compartment so that you know which sensor is going bad.

 

[PMG 705]

To clarify, when you say zero gas are you looking at the needle or does it actually say zero gas on your screen? With mine, once it goes below 30 miles left it shows ****.

My FX has always acted the way yours currently acts. The way you described it before your sending unit issues seems strange. Seem to be acting properly now.



TapaTalkin'

 

[kpaaaav]

MTN FX - I have been keeping the fuel log since I noticed the difference in how the fuel was being reported to me after they changed the sending units.

la-fx35 - I'll look into the DIY and if I can make time to try it this coming weekend, I will and i'll report back

PMG 705- When I say 0 gas, the needle is below the last line and the screen shows ---- , and then after driving it a lot more it says on the screen 0 Miles (Just like it did when the sending units went bad)

I've been reading about these cars having a reserve, like even when it says 0, you actually have a little gas. How much is that reserve supposed to be. I know for a fact before all these problems, my gauge and screen were dead accurate. When it said I was empty, I WAS EMPTY. Now not so much.

 

[matrixx860]

I have the first gen and have to say a few months back I had the same problem and ever since I did the fuel gauge level fix I have not had this problem again and if and when it does happen it will only take me about another 20-30 minutes to perform the fix again.

 

[IridiumFX]

I'm not a big fan of the gas guage going from 30 miles on the range to -- within a second. I use a great app called Gas Cubby. It allows me to document and track exactly how many miles I get per tank, how much I've been spending on gas, and actually fuel economy. I use it each time I fill up. Here is a screenshot of it:

 

[jdTrader]

I just installed gas cubby....can't wait to get some stats!

 

[jdTrader]

[video=youtube;yw51F6KlojA]http://www.youtube.com/watch?v=yw51F6KlojA[/video]

 

[frontier2005]

i dont know if this related to your problem. there's is a new bulletin for the 2nd gen FX35 for inaccurate fuel gauge. release last sept 2012. this bulletin is about replacing you fuel pump assemlby. taking out the old coil spring from the pump and puttiing it to the new pump. because your new pump only got 1 coil spring that push the assemlby down. so what infiniti came up to, is re-using the coil spring from the old pump and putting it to the new, so now pump got 2 coils spring to push it down evenly.

 

[aiya]

Is the new pump identical to the old one? If so, then supplying a new spring seems to be a much better option. :sluggish:

 

[frontier2005]

yes, it's similar .

 

[TurTLeG]

I'm not a big fan of the gas guage going from 30 miles on the range to -- within a second. I use a great app called Gas Cubby. It allows me to document and track exactly how many miles I get per tank, how much I've been spending on gas, and actually fuel economy. I use it each time I fill up. Here is a screenshot of it:

I've been doing this manually on excel every fill up since I bought my G. Its nice to know. Good app for the lazy ones.

Sent from my Galaxy Nexus 2

 

[NorcalFX]

My 2nd gen recently had this issue. Car was fine, then one day I started my car, and the gas gauge was on empty, and the digital reading in the dash said 0 miles. It did this for about 3 days, even after filling my tank up to full.

I was going to bring my car into the dealership, but they turned me away saying that my gas tank needed to be 1/4 tank full in order for them to perform the necessary checks on my fuel sending units. However, a few days later, the gas gauge went back to normal, and it's been fine for the last couple of days.

I'm not sure what's going on here, but would love to hear if others have had similar problems/issues. Luckily, the service rep saw my car's gas gauge at 0 miles, so I'm hoping they won't turn me away when I go in again to get it checked out.

 

[vicdub85]

My 2nd gen recently had this issue. Car was fine, then one day I started my car, and the gas gauge was on empty, and the digital reading in the dash said 0 miles. It did this for about 3 days, even after filling my tank up to full.

I was going to bring my car into the dealership, but they turned me away saying that my gas tank needed to be 1/4 tank full in order for them to perform the necessary checks on my fuel sending units. However, a few days later, the gas gauge went back to normal, and it's been fine for the last couple of days.

I'm not sure what's going on here, but would love to hear if others have had similar problems/issues. Luckily, the service rep saw my car's gas gauge at 0 miles, so I'm hoping they won't turn me away when I go in again to get it checked out.

My 2013 did the same thing with @ 50k miles. It is some spring in the sending unit. Hopefully you are still under warranty.

 

[NorcalFX]

My 2013 did the same thing with @ 50k miles. It is some spring in the sending unit. Hopefully you are still under warranty.

Oh man, thanks for your reply. I thought I was the only one this happened to. I am still under warranty, so even though it looks like it's fixed itself, I'm going to still bring it in to replace. My car is almost at 50k as well.

 

[TaborSpartan95]

Oh man, thanks for your reply. I thought I was the only one this happened to. I am still under warranty, so even though it looks like it's fixed itself, I'm going to still bring it in to replace. My car is almost at 50k as well.

I have a 2013 FX37 with almost 38k miles that started registering 0 miles till empty with check engine light late last week. I am still under the drive train warranty so it is in the dealership right now. They did not seem shocked or surprised so I'm guessing they have seen it before. They talked about completely replacing the fuel pump assembly. I mentioned the Technical Bulletin and they looked a little sheepish, but claimed Technical Bulletins don't necessarily indicate a systemic problem. Right...fingers crossed.