Fuel gauge doesn't work after tank swap

[G_Raw]

Alright family. I've been gone for a minute. I apologize about that. I need some help though. I punctured my stock skid and gas tank one Fordyce. I swapped tanks and gas gauge read full all the time. No prior issues with gauge prior to tank swap.

I pulled the tank again to inspect things and the fuel pump connectors ground wire was wonky ( brown wire). The blue rubber plug and connector pin could just be plucked on brown wire. Corrected that situation and my gauge read just over a 1/4 tank which seemed accurate(ish) based on miles per tank. I got everything buttoned back up and added 5 gal gas from a spare fuel tank. No change in gas gauge. Ran down to gas station added 3.8 gal and pump stopped meaning I'm full. Gas gauge still reading just over a 1/4 tank.

Pulled negative battery cable to reset things. No change. Ahmed the harness connector and with brown wire as ground and red and yellow wire next to it as positive it ohms at 4.99 volts with power on.

Where do I go from here to correct my gauge issue?

Thanks ahead of time for help.

 

[spartacus]

https://www.toyota-4runner.org/3rd-gen-t4rs/170717-fuel-gauge-off.html#post1719005

 

[G_Raw]

https://www.toyota-4runner.org/3rd-gen-t4rs/170717-fuel-gauge-off.html#post1719005

Thanks for the response but I've navigated that thread already. The TSB Durk mentions doesn't list my VIN as affected vehicle.

The folks in that thread also aren't solving an issue but instead using an Ultragauge to monitor the issues.

My issue isn't so much that the gauge doesn't read accurately. It just doesn't move. First round of reinstall it sat at full mark while empty and it never left the full mark even driving it a couple hundred miles.

So I thought the float must be stuck against something.

So I pulled it again this weekend and redid things. Plugged it in prior to reinstalling the tank and gauge showed just over a 1/4 tank. That seemed accurate. I took it down to the gas station to fill up and the gauge hasn't moved. Still just above a 1/4 tank.

Only thing I found during my inspection is the brown ground wire on the fuel pump harness was backed out. But I have since fixed the ground.

 

[Twan]

I just had the sender replaced in mine while the tank was out for a replacement. I smashed my stock tank and then it would only read between half and full. New tank and sending unit and everything is working as it should.

 

[Auce]

I literally just went through the same thing. The mechanic for got to re-plug in the sending unit.

 

[brillo_76]

I literally just went through the same thing. The mechanic for got to re-plug in the sending unit.

How can you forget to replug in a sending unit? Most have gotten side tracked. :/ Glad yours is working again.

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[Bad Luck]

Thanks for the response but I've navigated that thread already. The TSB Durk mentions doesn't list my VIN as affected vehicle.

The folks in that thread also aren't solving an issue but instead using an Ultragauge to monitor the issues.

My issue isn't so much that the gauge doesn't read accurately. It just doesn't move. First round of reinstall it sat at full mark while empty and it never left the full mark even driving it a couple hundred miles.

So I thought the float must be stuck against something.

So I pulled it again this weekend and redid things. Plugged it in prior to reinstalling the tank and gauge showed just over a 1/4 tank. That seemed accurate. I took it down to the gas station to fill up and the gauge hasn't moved. Still just above a 1/4 tank.

Only thing I found during my inspection is the brown ground wire on the fuel pump harness was backed out. But I have since fixed the ground.

As much as you don’t want to hear this, it sounds like you need to remove the fuel pump and move the float while checking the resistance values. That will tell you if it’s the fuel level sensor or the wiring out side of the tank.

 

[G_Raw]

As much as you don’t want to hear this, it sounds like you need to remove the fuel pump and move the float while checking the resistance values. That will tell you if it’s the fuel level sensor or the wiring out side of the tank.

No I'm prepared for that at this point.

I hate pulling this tank. I want to cut a hole in the floor pull the fuel pump and weld the floor back together once things are back together. It feels like less work but I'm just being a :baby:

 

[clearock]

not sure if I missed it or not but just to be clear, when u say u swapped the tank do u mean u picked up a used one with a pump, gauge sensor, and all or u mean u got a tank and moved all u shit over to the new tank? with all the wire issues I'd start with making sure the connections are actually holding/connected as wires shouldn't be "backing out"...

if u just swapped a complete unit the sensors in the tank have differences just like the 3rd gens vary over the yrs

 

[G_Raw]

not sure if I missed it or not but just to be clear, when u say u swapped the tank do u mean u picked up a used one with a pump, gauge sensor, and all or u mean u got a tank and moved all u shit over to the new tank? with all the wire issues I'd start with making sure the connections are actually holding/connected as wires shouldn't be "backing out"...

if u just swapped a complete unit the sensors in the tank have differences just like the 3rd gens vary over the yrs

Just swapped tank. Fuel pump and sending unit all mine just dropped in the new tank.

I ran through the wires and other than the brown ground wire that I repaired all looks well. But as suggested I should've tested resistance on the sending units harness and did not. So I'll do that this weekend. [MENTION=319302]Bad Luck[/MENTION] do you the the values on the resistance test for the sending unit?

 

[Bad Luck]

Just swapped tank. Fuel pump and sending unit all mine just dropped in the new tank.

I ran through the wires and other than the brown ground wire that I repaired all looks well. But as suggested I should've tested resistance on the sending units harness and did not. So I'll do that this weekend. [MENTION=319302]Bad Luck[/MENTION] do you the the values on the resistance test for the sending unit?

I couldn't find any specifications on that in my FSM, but I did find it on ProDemand. ProDemand says resistance should be 184 ohms full, 97 ohms half, and 12 ohms empty. If it ohms out okay, then I would recommend plugging it back in and having someone watch the fuel gauge while you manipulate the float.

 

[brillo_76]

I have pulled 3 3rd gen tanks thus far.. They are only bad if the bolts are rusted and the rust gets you.. 2 of my 3 came out amazingly without snapping bolts...:/ I was lucky.....:biggrin2:

 

[G_Raw]

I have pulled 3 3rd gen tanks thus far.. They are only bad if the bolts are rusted and the rust gets you.. 2 of my 3 came out amazingly without snapping bolts...:/ I was lucky.....:biggrin2:

They aren't bad. One of my bolts did snap on the second round of pulling this tank. My fuel line flare nuts are the pain. It's just no fun dropping it and lifting back in with fuel in them. Also whose bright idea was it to have the tank and skid plate share the same mounting points? Just not my fav gas tank setup to deal with.

With that said I also didn't enjoy my cousins XJ back in the day. We dropped his often enough that we ended up cutting a hole in the rear floor to access the fuel pump without dropping the tank.

I feel like if after this weekends third drop of the tank doesn't fix things...4runner gets a hole put in it :laser:

 

[brillo_76]

They aren't bad. One of my bolts did snap on the second round of pulling this tank. My fuel line flare nuts are the pain. It's just no fun dropping it and lifting back in with fuel in them. Also whose bright idea was it to have the tank and skid plate share the same mounting points? Just not my fav gas tank setup to deal with.

With that said I also didn't enjoy my cousins XJ back in the day. We dropped his often enough that we ended up cutting a hole in the rear floor to access the fuel pump without dropping the tank.

I feel like if after this weekends third drop of the tank doesn't fix things...4runner gets a hole put in it :laser:

That happens. Honestly, all fuel tanks pump fuel sending units etc should be accessible through bolt on panels. Just to make it easier to work on. The engineers should also have to take a rig entirely apart as well so they engineer things better when they mfg them.

 

[G_Raw]

Problem solved! First the story of the third tank drop...

Pulled everything out and removed the fuel pump and sending unit. Plugged it into the harness. Turned power on. Watched my gas gauge sit at empty. Raised the float arm to full. Gas gauge slowly crept to full. I then dropped the arm and watched the gauge empty out again.

Cool so in theory it should be fine. I was tired of pulling the tank every weekend so I tested resistance in the sending unit. My numbers match Bad Lucks listed above.

Cool so all clear. ray:

Put everything back together in to the tank and raids it up next to rear passenger door on trans jack. Plugged the harness in and turned power on... The gauge reads full. My tank is not full. :frusty:

Pull the pump and sending unit back out and inspect things. I don't see anything so I throw it back together. Turn on power and gauge is just under 3/4 full which is accurate for amount in tank based on miles per tank on odometer.

Time to throw this tank back up for the last time.

Get cleaned up and run errands with the wife in the runner and this gauge doesn't move at all. I'm driving 40 miles I should see some movement.

So I pull the tank again when we get home. That's when I pull the filler neck on the tank and watch through the hole as I drop the pump back in.

Turns out the wall the float should sit under a wall that has a groove that prevents the arm from going up past that (full)level. However when you have fuel in your tank and you angle the float and pump t logo back in back in it creates a scenario where your float can't pass the the wall cause its doing its job and floating which as you adjust angle to do final drop causes the float to lodge against this dang wall. Thus my gauge wouldn't move!!!!

Luckily the put holes in the wall so that you can use a long skinny tool of your choosing to reach through the filler neck note and slowly push the float down till it clears the wall.

Great!!! Now throw this pumper/sender and tank back together and strap it up under this rig. We go for a test drive to get some hooks, weights, and bait for tomorrow. Gauge starts at just under 3/4 which is accurate during the commute to and from home I go down to a half tank. Stop at a gas station and the gauge reads full!!!

 

[brillo_76]

Problem solved! First the story of the third tank drop...

Pulled everything out and removed the fuel pump and sending unit. Plugged it into the harness. Turned power on. Watched my gas gauge sit at empty. Raised the float arm to full. Gas gauge slowly crept to full. I then dropped the arm and watched the gauge empty out again.

Cool so in theory it should be fine. I was tired of pulling the tank every weekend so I tested resistance in the sending unit. My numbers match Bad Lucks listed above.

Cool so all clear. ray:

Put everything back together in to the tank and raids it up next to rear passenger door on trans jack. Plugged the harness in and turned power on... The gauge reads full. My tank is not full. :frusty:

Pull the pump and sending unit back out and inspect things. I don't see anything so I throw it back together. Turn on power and gauge is just under 3/4 full which is accurate for amount in tank based on miles per tank on odometer.

Time to throw this tank back up for the last time.

Get cleaned up and run errands with the wife in the runner and this gauge doesn't move at all. I'm driving 40 miles I should see some movement.

So I pull the tank again when we get home. That's when I pull the filler neck on the tank and watch through the hole as I drop the pump back in.

Turns out the wall the float should sit under a wall that has a groove that prevents the arm from going up past that (full)level. However when you have fuel in your tank and you angle the float and pump t logo back in back in it creates a scenario where your float can't pass the the wall cause its doing its job and floating which as you adjust angle to do final drop causes the float to lodge against this dang wall. Thus my gauge wouldn't move!!!!

Luckily the put holes in the wall so that you can use a long skinny tool of your choosing to reach through the filler neck note and slowly push the float down till it clears the wall.

Great!!! Now throw this pumper/sender and tank back together and strap it up under this rig. We go for a test drive to get some hooks, weights, and bait for tomorrow. Gauge starts at just under 3/4 which is accurate during the commute to and from home I go down to a half tank. Stop at a gas station and the gauge reads full!!!

Great Job glad you resolved the issue.

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