The fuel level indicator seems to be "stuck" at the mid-level point and there is no change in the indicator until the tank reaches about 3/8th. So it just jumps from 1/2 level mark to ~3/8 level mark after certain miles.

Just wanted to check if someone else have similar issue and to know more about it, before I take the car to the dealership.

 

Forgive me, but isn't it an 8-bar display? If so, doesn't that automatically imply that, at some point, it will "jump" from 1/2 (aka 4/8) to 3/8? Or are you talking about the non-linear relationship between the display and the amount of fuel in the tank? If the latter, we've discussed this before and it's due to the shape of the saddle-tank.

 

I'm not sure whether you are referring to 2008 center consoles, but mine is 2011 Evo X. So the indication level is bit more granular.

 

Ah, that makes sense. So, it's really making a sudden jump, eh? Well, the only thing I can think of trying before going to the dealer is this: next time that it has been stuck at 1/2 for a bit, go drive on a very bumpy road. If the float is getting stuck, this could free it and would tell you what they need to do.

 

I noticed that with mine today. It's been at sitting at a tiny bit below half tank for two days. I'm wondering if it will jump down eventually like yours. My miles to empty has been going down as normal though. Weird, no? Will update. I only have 700 miles on the car.

 

Wild-arsed internet theory time! Woo hoo!

Saddle tanks, as we have, do not have a linear relationship between fuel depth and fuel amount; once the level has dropped to the point of the saddle, there is less fuel per inch of depth than before. To compensate for this, the ECU must use a non-linear function to compute fuel amount from float height. (That much, so far, is sure. Here comes the wild-arsed theory.) If the point of non-linearity in the ECU's function is off, just as you reach the point of the saddle, which would be about a half-tank, there would be a brief incorrect relationship. That could be the problem here.

 

To fix this, it would be a simple change to the ECU, I presume?

 

Nope. If my theory is correct, it would require a person like Tephra to fix.

 

First time hearing about Tephra; my fault not digging much in the ECU section. Though I can spend sometime to know about this, just trying a shortcut here:

What's the advantage of using Tephra ROM for evo x?
Is there a reason why Tephra is not popular among evo x as much it is with evo 8 - 9? Or is it just my ignorance?

 

All I meant was that, if my theory is correct and a new function that computes fuel level from float height is needed, it would require the knowledge and skills of someone - such as Tephra - who has been "inside" the Evo X ECU. There may be others, with Vladimus being a possibility. But, really, all I meant is that this will not be simple by any means.

And please note that I have no idea if it's even possible to alter that function. I don't even know if we have identified the underlying problem.

 

Yup, I understand what you are saying.

 

Well to update, my fuel level started going down yesterday. It was confused for a few days. I only drive about 10 miles a day so for about 30 miles it was stuck at the same level - not as severe as your issue.

 

I had this issue once a couple months back but just disappeared
It doesn't smoothly go from Full to Empty but instead in sections
I honestly prefer the old school needle gauge method