Gas tank and mileage indicator issues...

[Tex-Tac]

Hopefully I can get a straight-solve-this-problem answer to this issue on my wifes 2003 4Runner.

The problem is this, sometimes (not all the time) when the gas tank is full the "low fuel light indicator" will come on and also the mileage indicator reads incorrectly? WTF!? This appears to be an intermitten problem.

I've searched here in T4R.org for a solution to this problem and most answers appear to be guessing or try this, I heard, I read, or try that, etc.

What I really would like is a direct answer-solution to this problem.

Please don't recommend that I call the dealership because all they'll do is tell me to take it in, blab, blab, blab and try to stick it to me for a lot of $$$$$.

Thanks for your help!

Anyone?

 

[Mike W]

Does your actual fuel gauge work correctly and move fluidly? Or does it move erratically/not function at all?

 

[marc_l71]

low fuel light could be that your sensor(older vehicles-a float) in the tank is bad( means drop tank and replace) especially with having a full tank of gas.

 

[Tex-Tac]

Does your actual fuel gauge work correctly and move fluidly? Or does it move erratically/not function at all?

Yes, sometimes the actual 'gauage gas indicator' will give an incorrect indication as well. Example, the gas tank is full of gas but the guage indicator will show half-tank or 1/4 of a tank of gas. But for most of the time it reads correctly?


Thanks fella's for your reply's! I'm very appreciative of them.

 

[Mike W]

Yes, sometimes the actual 'gauage gas indicator' will give an incorrect indication as well. Example, the gas tank is full of gas but the guage indicator will show half-tank or 1/4 of a tank of gas. But for most of the time it reads correctly?


Thanks fella's for your reply's! I'm very appreciative of them.

Yep, looks like the sending unit in the tank is bad. I'm not sure of access points on the 4th gens, maybe someone can point out if the rear cargo area/rear seat area carpet can be pulled up to reveal the wiring harness that could possibly be unplugged and ohmed out to test if it is bad or not??

Either way, looks like the tank will need to be dropped and the sending unit replaced. Can't be too bad of a process...run the tank down to 1/4 or less (actual, not based on the gauge...calculate roughly by mileage traveled and the MPGs you know you get), loosen filler neck and vent lines, remove tank skid, loosen straps for tank, lower with two floor jacks and some boards for cribbing, and replace the unit.

Then again, it's always easier on paper. Best of luck man

 

[marc_l71]

Yes, sometimes the actual 'gauage gas indicator' will give an incorrect indication as well. Example, the gas tank is full of gas but the guage indicator will show half-tank or 1/4 of a tank of gas. But for most of the time it reads correctly?


Thanks fella's for your reply's! I'm very appreciative of them.

maybe a short someplace?

 

[Tex-Tac]

Thanks guys!

Now I know more or less on how to approach and start trying to solve this problem.

 

[Ask10]

Yep, looks like the sending unit in the tank is bad. I'm not sure of access points on the 4th gens, maybe someone can point out if the rear cargo area/rear seat area carpet can be pulled up to reveal the wiring harness that could possibly be unplugged and ohmed out to test if it is bad or not??

Whatever pics you want of a stripped out interior, let me know. My interior is gutted completely (down to the carpets) because I use mine as a sort of work truck/cargo "van". However, I don't see anything in terms of access point to the wiring harness. I am thinking you'd have to drop the tank to reach the wiring harness.

 

[Tex-Tac]

Whatever pics you want of a stripped out interior, let me know. My interior is gutted completely (down to the carpets) because I use mine as a sort of work truck/cargo "van". However, I don't see anything in terms of access point to the wiring harness. I am thinking you'd have to drop the tank to reach the wiring harness.

If you can and are willing to provide pictures, yes I'd appreciate it very much?!

I was hoping that I could gain access from removing the rear seat and pulling back the carpet to gain access in order to remove and replace the gas tanks sending unit? But if not, then it appears as though I'll just have to bite it and drop the gas tank in order to remove and replace it. Hey I was just trying to find the easiest, straight forward process but as we all know that nothing is ever easy.

EDIT: Just called the 'Stealership' and the price quote for the 'gas tank sending unit' alone is around $100 bucks, part number: 8332060440 (2003-2009 4Runners) and it would have to be ordered.

 

[wyanrard]

[MENTION=45064]Tex-Tac[/MENTION]
On a serious note, have you pulled the fuse for the dash gauges, started it with the fuse out, shut it off, put the fuse back in and started it again? My gas gauge freaked out on me a while ago. It was showing full when I know i only had a half tank. Seemed to fix the problem.

 

[Tex-Tac]

[MENTION=45064]Tex-Tac[/MENTION]
On a serious note, have you pulled the fuse for the dash gauges, started it with the fuse out, shut it off, put the fuse back in and started it again? My gas gauge freaked out on me a while ago. It was showing full when I know i only had a half tank. Seemed to fix the problem.

Where exactly-specifically is the "fuse for the dash gauges" located at?

Is it under the dash, engine compartment or ?


Thanks for the tip! I'll first give this a try and see what happens. Hopefully it'll correct the problem, if not then I'm still going to have to order the part and drop the tank.

 

[BlackWorksInc]

They don't go bad nearly as often as GM trucks (man, that's easy money for me! Almost every GM BoF used vehicle we get has fuel pump/fuel sender issues! lol) but they do go bad. This sounds like the fuel sender unit is going out. The fuse should be labeled something like Instrument Panel or something similar. The Owner's Manual has a detailed description of the fuse locations and what they do.

 

[Tex-Tac]

They don't go bad nearly as often as GM trucks (man, that's easy money for me! Almost every GM BoF used vehicle we get has fuel pump/fuel sender issues! lol) but they do go bad. This sounds like the fuel sender unit is going out. The fuse should be labeled something like Instrument Panel or something similar. The Owner's Manual has a detailed description of the fuse locations and what they do.

Yea, I already found it's location from the manual so I'll just check into it tomorrow.

Anyway thanks for the tip!

 

[Ask10]

Sorry, just got home.

**I was wrong on the access point, it does have an in-cab access point.**

Okay, the back seats have to be unbolted from the body itself because the carpet is "secured" by the seats themselves. Don't know if that made sense. Just trying to say that the carpet doesn't pull up with the seats in place.

Anyway, after the seats are out (heavy), pull up door sill plastic and the carpet should just come off. Mine had little hooking tabs on it and it took me a second to figure out I had to unhook it before it folded over. Seems like access is a breeze after that.

 

[BlackWorksInc]

Sorry, just got home.

**I was wrong on the access point, it does have an in-cab access point.**

Okay, the back seats have to be unbolted from the body itself because the carpet is "secured" by the seats themselves. Don't know if that made sense. Just trying to say that the carpet doesn't pull up with the seats in place.

Anyway, after the seats are out (heavy), pull up door sill plastic and the carpet should just come off. Mine had little hooking tabs on it and it took me a second to figure out I had to unhook it before it folded over. Seems like access is a breeze after that.

Its been a while since I looked at the 4Runner fuel pump assembly, but is that access panel large enough to remove the fuel pump unit from inside the tank through or just to gain access to the wiring and connections? Because the entire fuel pump assembly needs to come out like GM trucks to pop the fuel sender off and that black cover looks far smaller in diameter than the usual fuel pump unit we use.

 

[Ask10]

I thought the sending unit on 4th gens didn't require the removal of the pump, but now you've got me wondering...I'll go digging through what I can find to see. I have a service manual somewhere...

 

[Tex-Tac]

Cool! :reddance:

Thanks for taking the time to post the pictures.

Looks like "just maybe" I won't have to drop the gas tank in order to gain access to the gas sending unit? :shrug:

Its been a while since I looked at the 4Runner fuel pump assembly, but is that access panel large enough to remove the fuel pump unit from inside the tank through or just to gain access to the wiring and connections? Because the entire fuel pump assembly needs to come out like GM trucks to pop the fuel sender off and that black cover looks far smaller in diameter than the usual fuel pump unit we use.

 

[BlackWorksInc]

I thought the sending unit on 4th gens didn't require the removal of the pump, but now you've got me wondering...I'll go digging through what I can find to see. I have a service manual somewhere...

I could be wrong, but most of our fuel pumps seem to be a in tank unit with the fuel level sender mounted to the side (it is replaceable separately), which means it has to come out with the entire unit.

I don't remember the last time I did a J120/J150 vehicle so I couldn't tell you for sure about how our fuel pumps/senders are set up, just how Toyota does the Tundras and other vehicles.

 

[Ask10]

I could be wrong, but most of our fuel pumps seem to be a in tank unit with the fuel level sender mounted to the side (it is replaceable separately), which means it has to come out with the entire unit.

I don't remember the last time I did a J120/J150 vehicle so I couldn't tell you for sure about how our fuel pumps/senders are set up, just how Toyota does the Tundras and other vehicles.

Probably the same then. I can't remember ever needing to dig into any of my Toyota's for a fuel pump honestly except my very old Corolla, and even then I couldn't tell you if the sender required dropping the tank or not. Too reliable I guess.

And sorry OP, I can't find my manual. If I get a moment I'll have a look at the cover and see if I can see anything telling.

 

[Tex-Tac]

Probably the same then. I can't remember ever needing to dig into any of my Toyota's for a fuel pump honestly except my very old Corolla, and even then I couldn't tell you if the sender required dropping the tank or not. Too reliable I guess.

And sorry OP, I can't find my manual. If I get a moment I'll have a look at the cover and see if I can see anything telling.

Hey, that's alright, it's all good.

If time allows you too then great, if not, that's O K.

Even if you can remove that black top cover to see if access is possible? Could be that the entire fuel pump on the 4Runner (2003-2009) is smaller than other vehicles that have'em larger, so as to avoid dropping the entire gas tank?
The reason why I say this is because in the pictures that are posted, if you had to drop the tank just to gain access to the fuel pump and gas sending unit then it looks like you would just about also have to remove the back seat to push the carpet back in order to 'disconnect' the sending unit's connection? That looks like double the work?!
I guess the only way to know for sure is to look at a Service Manual on a 2003 4Runner?

EDIT: Well after looking over a Haynes Repair Manaul for 2003-2009 Toyota 4Runners, it looks as though I've finally found confirmation on the removal-installation process of the gas sending unit. The gas tank will have to be dropped and the back seat will have to be removed in order to gain access to disconnect the connections on top of the fuel pump. Damn, double the work!