I have conducted a thread search and could not find this problem listed so i thought I would share our recent experience with the fuel gauge sensors in our 2007 GXL.
We purchased the vehicle privately in February 2011. Shortly after this we started to notice that the vehicle was showing almost empty on the fuel gauge but when we went to fill the car it would only take about 80 litres. This restored the gauge back to full. Not really being familiar with the fuel system and after referral to the manual we just thought it might have been an anomaly.
The gauge then dropped rather quickly again after only a week or two of running around (about 900 kms) and when I went to fill it it would only take about 50 litres again restoring the gauge to full.
This time we again we got about a week (400 kms) before the guage again had moved rather quickly back to empty so on the third occasion I went to fill it, it would not accept any more than about 7 litres of fuel before the filler tube to the tank bubbled fuel back. On this occasion though the gauge did not reset and was still showing empty. Rocking the car did nothing to assist and the fuel tank filler tube did not have any obstructions.
I dutifully consulted this forum and came across the thread relating to the fuel pump located in the main/sub taknk whose role is to pump fuel from the sub as the main drains through use. The symptons we were experiencing matched those (gauge showing empty but vehicle would not take any more fuel) so we thought that the problem must have been a faulty pump or blocked filter that was causing an airlock preventing the main tank from filling.Thankfully I went to our local Repco repairer (Rolys Automotive Berri) rather than our local Toyota dealer else this exercise may have been a lot more costly that it turned out to be (again, thanks to those who posted in the fuel pump thread and warned others of the Toyota dealers approach to these sorts of problems).
The mechanic removed both tanks and noted that both were full. The fuel pump and filter were fine and functioning correctly. They then started tracing the fuel gauge sensor route and found that there are two. One in the main tank and another in the sub (I think this is where he said it was but it might have been further up the driveline). The main tank sensor was a ball/float system and is connected to a small circuit board and depending on the level of the tank, the arm moves up and down a small board and changes the level of resistance to indicate fuel levels.
The information from this sensor is then sent to the second sensor and then onto the fuel gauge. In our case the float arm had broken from the solder of the board and thus was not sending a true reflection onto the second sensor hence the incorrect reading. The mechanic was not sure but thought that this may have affected the fuel tank pump's functioning in transferring fuel from the sub if this problem was not corrected.
This took a couple of days of diagnostics at their workshop but of interest was when they referred to the Toyota repair manuals, the approach that was recommended was to conduct a series of checks and virtually replace items as you move through the fuel system if the problem was not rectified. This would have necessitated, in our situation, a new fuel tank pump/filter, sensors and even a new fuel gauge in the dash. A very costly proposition indeed. When they consulted with other Toyota dealers none of them had seen this problem before hence this post for info of members.
Whilst they had the car on the hoist they did note a scuff mark to the fuel tank protector plate. The mechanic thought that if the car had bottomed out in this position with some sort of force this may have caused this problem. Given we have not yet taken the car off road we can't be sure if the previous owner had done so but it appears to them that a blow of some force to that area could manifest this problem in the absence of any other indicators.
This is our first post but so far we have obtained a lot of information from other member's experiences so we thought we would share one of ours. Forwarded for the info of all should you get a similar problem.
We purchased the vehicle privately in February 2011. Shortly after this we started to notice that the vehicle was showing almost empty on the fuel gauge but when we went to fill the car it would only take about 80 litres. This restored the gauge back to full. Not really being familiar with the fuel system and after referral to the manual we just thought it might have been an anomaly.
The gauge then dropped rather quickly again after only a week or two of running around (about 900 kms) and when I went to fill it it would only take about 50 litres again restoring the gauge to full.
This time we again we got about a week (400 kms) before the guage again had moved rather quickly back to empty so on the third occasion I went to fill it, it would not accept any more than about 7 litres of fuel before the filler tube to the tank bubbled fuel back. On this occasion though the gauge did not reset and was still showing empty. Rocking the car did nothing to assist and the fuel tank filler tube did not have any obstructions.
I dutifully consulted this forum and came across the thread relating to the fuel pump located in the main/sub taknk whose role is to pump fuel from the sub as the main drains through use. The symptons we were experiencing matched those (gauge showing empty but vehicle would not take any more fuel) so we thought that the problem must have been a faulty pump or blocked filter that was causing an airlock preventing the main tank from filling.Thankfully I went to our local Repco repairer (Rolys Automotive Berri) rather than our local Toyota dealer else this exercise may have been a lot more costly that it turned out to be (again, thanks to those who posted in the fuel pump thread and warned others of the Toyota dealers approach to these sorts of problems).
The mechanic removed both tanks and noted that both were full. The fuel pump and filter were fine and functioning correctly. They then started tracing the fuel gauge sensor route and found that there are two. One in the main tank and another in the sub (I think this is where he said it was but it might have been further up the driveline). The main tank sensor was a ball/float system and is connected to a small circuit board and depending on the level of the tank, the arm moves up and down a small board and changes the level of resistance to indicate fuel levels.
The information from this sensor is then sent to the second sensor and then onto the fuel gauge. In our case the float arm had broken from the solder of the board and thus was not sending a true reflection onto the second sensor hence the incorrect reading. The mechanic was not sure but thought that this may have affected the fuel tank pump's functioning in transferring fuel from the sub if this problem was not corrected.
This took a couple of days of diagnostics at their workshop but of interest was when they referred to the Toyota repair manuals, the approach that was recommended was to conduct a series of checks and virtually replace items as you move through the fuel system if the problem was not rectified. This would have necessitated, in our situation, a new fuel tank pump/filter, sensors and even a new fuel gauge in the dash. A very costly proposition indeed. When they consulted with other Toyota dealers none of them had seen this problem before hence this post for info of members.
Whilst they had the car on the hoist they did note a scuff mark to the fuel tank protector plate. The mechanic thought that if the car had bottomed out in this position with some sort of force this may have caused this problem. Given we have not yet taken the car off road we can't be sure if the previous owner had done so but it appears to them that a blow of some force to that area could manifest this problem in the absence of any other indicators.
This is our first post but so far we have obtained a lot of information from other member's experiences so we thought we would share one of ours. Forwarded for the info of all should you get a similar problem.
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