Fuel sender issues? really need help & advice

[Malzy]

Sorry if this is a little long winded, this issue is doing my head in and your infinite subby wisdom would be greatly appreciated.

I've had my sexy mica black/silver 91 BC4 VZ legacy for 6 months now, when I first picked it up I would get about 400~450km between fill ups and the gauge would report that correctly. After a month or so I would get 300kms; I put down to my heavy foot at first, but now I now somethings wrong and I'm only getting 200kms (according to the gas gauge)!

It's like the gauge reads perfect but at a rate of x2 compared to whats in the tank < hope that make sense lol

I filled up yesterday to the brim as the tank was reading between empty and 1/4, where I normally fuel up fuel; and I only got 34 liters in the tank, that can't be right can?

I'm sure the fuel tank in my JDM is 60 liters, am I wrong? or is there an issue with the gauge or the sending unit?

The gauge drops like its reading correct ie not erratic like some I've heard about on these forums.

[07Evolved]

i know that the fuel "reader" in the tank wears out after a while. mine is starting to go as well. it is connected to the whole fuel pump system under your rear seats. it looks like a curved piece about 2 inches long that has metal contacts all down it. mine looked like some of the contacts are wearing out and that is what reads your level of fuel.

pick one up at a junkyard.

[Malzy]

Wow thanks for your fast reply

Is the sender/pump behind the rear seat on the right, under the oval-ish plate? (Sedan)

I'm a bit iffy about working around the fuel tank, is there anything I should know before pulling out the pump to check the sender? Will this expose me to the fuel/vapor?

Lee

[07Evolved]

The whole fuel pump assembly is located under the oval-ish plate you speak of under the rear seats on the passenger side. When I changed out my fuel pump, I just unhooked the battery to make sure I wouldn't get any random spark or static electricity. This process will expose you to fuel vapor, yes. Just be careful and take your time...it isn't hard to do.

[Malzy]

Cheers man I appreciate your help I'll check it out tomorrow; right sides the drivers side for me

[07Evolved]

no problem

i forgot about you guys down there driving on the wrong side...lol...just messin' with you man

best of luck

[BSOD2600]

Before you go buying a used sender, try cleaning it. Take an eraser and rub off the crap on those metal bars. I did it on my sender during the Walbro swap. Never had an issue with fuel gauge accuracy.

[Danny-G]

im in some what the same boat with the gauge not working right, when i started driving my car about two years ago the gause would go to full and down to empty but it was not accurate inbetween full and empty. the fix that i tried was junkyard sedning units which did the same thing, then my dad got me brand new sedning unints from the dealership for christmas and since i put the new ones in the gauge started out being erratic(it would say empty when i just filled the tank), since that time it would stop lower down each time till now it no longer goes to full(it stops at half normally when i fill the tank all the way). the thing i dont get is when it was being erratic i took the sending units out of the tank, moved them to full and it was just fine with the units out of the tank, once i put them back in it was back to being erratic. does anyone have an idea what could be causing this? im about ready to buy an aftermarket gauge and put it over the stock one

[Legacy777]

There's two senders, one on the passenger side and one of the driver's side. Either or may be the culprit. I ended up replacing both of mine because I got tired of the problems with the gauge.

[kimokalihi]

If you remove anything from the tank be careful when doing anything with the hoses on the outside. They can be brittle or not come off easily and it's not hard to destroy one trying to get it on and off. They run out of reach under the car and it's not fun replacing them when you have to drop the tank which requires removing the rear sub frame and axles and rear diff I believe. Not fun I just did it a while back.

[Malzy]

Thanks for all the advice guys

Also, is it true I only have the one sender in the FWD? I have the 2 covers on both left and right sides. I've not pulled it out yet I but will soon as the rain stops.

Funny thing is most people report their gauges as erratic where is mines perfectly linear in reading from say full to empty; it's just that its dropping to fast.

Another thing was it not reading full, even when I've brimmed it, the needle sits a couple nicks below

[Malzy]

Well, all done and dusted. Was fairly easy to do just awkward. kimokalihi's right about the lines, mine are still in good nick but what b*tch to get off.

I lost some fuel under pressure, forgot (or didn't think) to loosen the the fuel cap, lesson learned.

I thoroughly inspected the sender, pump and everything in between, then cleaned the contacts it was stained a turd brown colour from years of reading up and down, tis nice and shiny now.

I'm really not sure if it solved anything yet, if not the next step is to get a replacement unit

Lee

[Malzy]

There's two senders, one on the passenger side and one of the driver's side.

Legacy777" is it true for the FWD? I thought there was two only in the AWD as the tanks were different shape?

[Legacy777]

There's two senders, one on the passenger side and one of the driver's side.

Legacy777" is it true for the FWD? I thought there was two only in the AWD as the tanks were different shape?

You're correct, there's only one sender on the FWD. I must have missed that part in your post.

[91Beater]

Mine's definitely acting in the middle range. The amount it takes to replenish from "half full" is dramatically different each time. Sometimes, 6, sometimes 10 gallons.

What's the part # for 91 FWD? Our cars must be using a return style fuel injector, so the tank builds up pressure. I know this as after the car is driven, it lets out a fairly good woosh when the cap is loosened.

Do I need to take special steps or precautions to ensure good seal between the assembly and tank? I really don't want fuel vapor leaking into the car as the tank builds up pressure.

[Legacy777]

The sender/pump setup is the same as the AWD. The only difference is the resistance of the actual sender.

The original part # for the FWD sender is 85111AA140

However when you look it up, it says to use 85111AC051