Faulty fuel gauge

[g_man1972]

Hi all,

I have been putting up with a completely inaccurate fuel gauge for a while and thought i'd ask if anyone has any ideas. Basacally after I fill the tank, my guage never shows full, but around 3/4 and it goes down from there, ex I have 250 clicks since my last fill and my gauge shows less than 1/4 already. No my mileadge isn't that bad, because I can let it run down to the empty line, then it gets completely full after around 50-60l (auto tranny) so it seems like there is a part of the tank that isn't be read? Anyone have any ideas for what to check? I'm not interested in dropping the fuel tank and going inside it for what is a minor inconvience, but if it could be something simple I'll give it a go. Another clue is that when driving it fluctuates hugely, like from 3/4 to 1/2.

Thanks and i hope the vancouverites are finally enjoying the sun!
Cheers Gary

[nxski]

I have the exact same problem! Sorry, I don't have a solution but would love to know what it is.

[NoDelie]

From what i can tell from the posts your sending unit is working and your gauge is working. The only problem now is the float attached to the sending unit solid or hallow , if it is hallow it has cracked and fuel has got inside it there for weighing it down. That is one of the things that can set the gauge off kilter.

[g_man1972]

From what i can tell from the posts your sending unit is working and your gauge is working. The only problem now is the float attached to the sending unit solid or hallow , if it is hallow it has cracked and fuel has got inside it there for weighing it down. That is one of the things that can set the gauge off kilter.

And I suppose there is no easy way to fix that is there? Can it be removed to check? Sorry for the basic questions, never had to check something like that before.

Thanks for your reply and glad that I am not alone

Go Canucks go!

[thedjjack]

It can also be a bad section on the sending unit resistor. Pretty typical problem new sending unit and float will fix it.

[jaggedfish]

Obviously your sender unit is not sending correct info. I would agree with Thedjjack that one of the upper resistors has packed it in. The float could also be the problem but I think if it was sinking, it would likely sink all the way eventually. Sounds like it reads correctly near the bottom of the tank.

If you are trying to avoid removing the tank with the sender (there are 2 tanks), you are best to use your trip odometer as an indicator of how far you have travelled. Typically 500 to 550 km should take you to the empty line and would be about 55 to 60 litres to fill. The tanks hold 75 litres so there is a built in margin of error.

If you decide to drop the tank, make sure BOTH are drained prior to undoing any lines. If you don't, you will wear the contents of the other tank. I had to replace the rear tank on my L300 when I had it. Draining is tricky (and potentially messy) if you don't have the van up high enough.

[g_man1972]

Okay, well that's too bad. I was hoping that there was something that I could just unplug, unscrew and replace but I guess not. I will just leave it as is, maybe next time it's up on a hoist i'll feel inspired to give it a look.

Thanks for your replies.

[g_man1972]

We all know and love the querky ways of our vans, so I have an update.

I have been dealing with this faulty fuel gauge for probably around a year now, but just a few days ago I filled up as normally and guess what? Yup, it is working perfectly again with me doing squat to it. Im just above 1/2 tank and have 220kms driven, previous to this I would have been just above the E line. All I can think of that may have fixed it is that I usually park facing down hill, but my spot was taken, so I had to use the other side of the road facing up. My tank was fairly empty at this point, wonder if it somehow allowed gas to drain out of the sensor or something.

Anyway, just wanted to share as it's pretty funny how it fixed its self, who knows maybe it will help someone else in the future, faulty fuel gauge, park facing up hill for a day or two

Have a good one
Gary

[TardisDeli]

electrickerly

[dfnder]

Well I also have differing readings on my fuel gauge. When full it normally reads 3/4 yet sometimes returns to the F mark. Typically around 200-250Km it is at the 1/2 mark.

Sunday I was out to Langley for a visit, on the way home I noticed we were getting low on fuel. Asked my daughter if we should go on an adventure and not refuel - Much to my delight she suggested YES! It turns out that we made it home and the trip meter read 681 KM which is a new record for me.

I did have 3-4 litres of engine oil so I was sort of cheating hehe. Also my speedo does read 93.75% faster than my gps says so it was likely around 630KM that I traveled. On fill up I put in about 16L of Veg and 50L of diesel.

cheers

[ExplosiveAbe]

I too have a faulty guage & use the trip odometer to tell when to fill up.

I'll fill my tank & the guage never goes above 3/4. Other times I'll fill & it will just stay on empty. I blame my wife & kids.

[Luisito]

Hmmmm... this is making me wonder. When I first got my van a few weeks ago, I was putting about 600 kms on a tank, even on rough roads and hills. Now it is looking like 450-500 kms. Is this variability normal? What's normal mileage for an L300?