For a while now i've had a problem where my fuel level would change by half of a quarter while getting onto the highway. Tested my ohm range levels on primary and secondary fuel sending units and the secondary was off so i got a new one [thanks CBRD]

Fuel level now barley fluctuate's under all driving conditions, but when i reach anywhere close to my last 1/4 of the tank it the needle drops like crazy. What i mean is, it will be at its lowest point where it doesn't matter if the car is running or not, it'll just sit at the very bottom, i STILL drive another 30-40KM and decide its time to get gas, and yet can fill a MAX of 48L out of the 55L.

Anyone have any clue what might be causing this? No its not a BIG issue at all, but i like things working and working right on my car.

 

mine kind of does the same but at 1/4 mark it doesnt go lower and it will just run out of gas still saying 1/4 tank fulll. i go by miles now. the gauge sucks.

 

Try swaping gauge clusters. See if this helps

 

lame... i can't stand not knowing how much gas i actually have



i wouldn't mind swaping out the cluster if i can get one for a resonable price somewhere..

 

If my fuel gauge wasn't accurate I'd go crazy

 

i tried swaping out the cluster and i just ended up with different miles and the same messed up gauge. it has to be the fuel floater.

 

... so lame. i might try and replace my primary fuel sending unit, the whole thing and see what happens... but it seems to be in perfect condition, and the ohm range reads PERFECT on both primary and secondary, so little hope left in that area. but worth a try.

if i come across anything, or i figure anything out, ill be sure to post.

dj

 

Is yours modified at all or still stock? That sounds like a siphon issue

 

Is it the stock fuel sending unit on both sides? Siphon modified? Anything other than a single 255? Have you tried modifying the arm that holds the float to see if that matters? Is it actually reading right from above the full line down to 1/4 then just sinks to the tip of the E and sits there? What if you're driving as it drops, does it just sink or does it read accurately then when you shut it off and restart it doesn't move back up?

 

you do realize that 1/2 of 1/4 is 1/8 right? lol you could have just said that.

 

To my knowledge;

- Stock fuel sending unit both sides

- Siphon modified ; i have no clue. i never touched it. what do i look for and where's this located

- Just a single 255

- I haven't tried modifying the float as it seems to be in like new condition. and if i bend it at all, it would affect readings throughout the entire range of fuel level

- Seems to read fine from full tank all the way to the last 1/4 tank, and then it doesn't just sink, but it does drop a lot quicker. ie; every 1/4 tank i get roughly 50-60miles depending how i drive, but last 1/4 tank i get about 25-30miles. after the 20-30miles it will be buried past the empty line and i'll drive for another 10-20 miles, go to fill up and i can only put in (most i've filled up was) 48L / 55L. so obviously i still have 7 liters in there after driving on Empty according to the level gauge.

- After i stop, restart it, it doesn't make a difference

if it helps at all, it does take a lot longer for the fuel level in my cluster to show how much gas i have left when in the 1/4 tank section; ie: ill sometimes have to drive or have the car on for about 5mins+ for it to show exact gas, when tank is above the 1/4 tank mark, it normally shows the exact amount faily quickly, the more fuel the quicker it shows how much

i was thinking maybe its the fuel filter, but i just don't see how that would affect the reading, on top of it all when i did remove the whole primaly fuel assembly, the filter did appear to be clean and in good condition, not clogged in anyway so that shouldn't be the problem

if i dont come up with anything new to try, i may just try and grab a new primary fuel assembly.

*LOL* i dont know, just came out that way "half of a quarter" lol haha, .. next time.. next time



thanks to all for the info

dj

 

Honestly to me it's sounding more and more like a siphon issue but not sure how it would just creep up like this.

The Evo tank is a saddle tank. You have 1/2 of the tank *roughly* on each side of the drive shaft. The passenger side is basically a holding cell. There is no fuel pump mechanism over there, only a float with a suction tube more or less. The fuel pump turns on and pushes fuel to the feed side of the rail, through the rail, then out the return line. The movement of that fuel is tied into the single fuel line that runs into the passenger side fuel assembly. The force of that fuel coming back into the driver's side of the tank acts on that line and creates a suction on the passenger side tank and pulls fuel over into the driver's side to keep the tanks even more or less.

I'd be curious to see the results of this - when your tank says empty and the needle is bottomed out pull both assemblies and see if the passenger side has alot of gas and the driver's side has very little or vice versa or are they pretty similar.

During hard right cornering the gas can slosh over the middle hump into the driver's side of the tank from the passenger side so if it isn't reading right I wonder if that is partially what's going on. This is the siphon in the picture, the white h (turned upside down) shaped piece. It's fed by the fuel return line and by the hose from the passenger side of the tank. Usually when someone hits 1/4 of a tank and runs out of gas it's because they reversed the lines on this part, you can see the correct orientation in this picture. Is it possible you have this piece reversed so the long side is on the left and the short piece is on the right? If so the siphon can't function properly.

 

thanks for the great info. im almost half way done with this tank, so when i bottom out, i'll do as you said, ill remove both primary and secondary assembly and check how much gas is in both tanks(sections).

the siphon in the picture, H turned upside down, i feel retarded, cause i dont see no H lol ;/

but again, ill compare the picture to my assembly and see whats going on.

ill keep this updated as soon as i hit empty

edit; i think i see the H, which is the "h" which has the two hoses connected to it?

Found the picture i took with my iphone when i took it out while back, and seems the hose's are connected the same way, doesn't look any different.



Picture's upside down, booo ;/

For some reason im starting to think its all due to the siphon, somehow it isn't distributing the fuel evenly giving a bad read or something along the lines. Once i check the tanks when my fuel level is buried in the Empty zone, and that's all good, i might start looking for the primary fuel assembly excluding the fuel pump itself.

thanks again