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Fuel Tank Sending Unit

10K views 6 replies 4 participants last post by  l33ch 
#1 ·
The fuel gauge on my 05 Echo has just started to react very slowly. I filled the tank a few days ago, and it took about 20 KM's of driving for the gauge to move from near empty to full. Now after about 170 Km's, it dropped two bars on the gauge all at once. This happened all of a sudden, and I haven't done anything to the vehicle other than add fuel. I gather the fuel sending unit, filter, and pump are all accesible from an access plate under the back seat. I have found info and pictures of the filter and pump, but nothing specific about the sending unit. Does anybody know if it is attached to the filter and pump assembly, or is it a separate piece in the same area? From what I have found, a Denso Part # ND1748391 seems to be the sending unit. Anyone know if this is correct?

Thanks for your help!
Leo
 
#2 ·
I would check the rubber gasket on the gas cap. If the pressure is not there it could effect the sending unit to the gauge.

First thing replace gas cap gasket drive it for a few days and see if your problem doesn't go away.

Next, I would check the fuses for the sending unit...

Then I'd take a look at the fuel pump and maybe replace the sending unit if it's replaceable?

http://www.michaelchow.com/techinfo...toypdf/02rmsour/2002/02echorm/sf/fpr/comp.pdf
 
#3 ·
Hi Ericlp

Thanks for the tips. I am pretty sure the fuses are OK. I only see two listed that have anything to do with gauges, and they both also cover other items that work OK. I checked the gas cap gasket and it looks fine. I cleaned it and the mating surface up and put some silicone spray on the gasket. I 'll give it a try and go from there.

Thanks again!
Leo
 
#4 ·
Fuel Gauge Working Great

Hi Ericlp

Just wanted to let you know that my Fuel Gauge is working great now. I'm guessing that the Gas Cap Seal was the problem. It seemed to take a few kilometers to sort itself out, but than the gauge started following the level down correctly, and after I filled up today, the gauge went right up to full.

Do you know what the connection is between the Fuel Level Sender and the Gas Cap sealing correctly? I have attempted to sort it out in my mind, but I can't figure out the connection.

At any rate, Thanks very much for your help. I would never have thought of this.

Cheers
Leo:gaydumbo:
 
#5 · (Edited)
Aloha Leo,

Glad your Fuel gauge is working again! Your welcome. I think the problem is if the gas cap doesn't seal correctly it loses pressure and you can see that there is a vapor pressure sensor next to the sending unit guage. I'm sure that the computer measures the pressure of the tank to get an accurate reading of the gas level in the tank.

Glad to have helped you out.
 
#6 ·
Hi guys, figured id carry this one on seeing as i am having a similar issue but i just replaced my whole fuel filler hose, i picked up my 05 echo (4 door hatch) last december, and its now pushing up on 400,000km, but when i got it the only thing i have yet to fix that did not work is the fuel gauge. when i did the fuel pump i noticed the fuel sending unit didnt look like it was in the best shape, the conact surface where the floater arm touches the unit to pass resistance seemed to be, well, scraped off likely just worn down from thousands of leters of fuel used, my question for all of you is, where can i find a new fuel sender unit? Canadian tire has them but they come with a fuel pump (which i just replaced 4 months ago now) and runs up a nice hefty price tag of $600. Iv seen after market ones online claiming ultimate compatibility and showing resistances of 0-60Ohms, and up to as high as 0-130 Ohms, and knowing resistance, these parts are not interchangeable (seeing as sure 0 ohms is still empty, 60 could be full, but displaying full until i only have 1/4 tank left then itd drop super fast due to the lack of accuracy in the needed ohm range)

and since im writing this anyways, i figure ill ask, in the event noone really can find the manufactures equivalent, what are the specs on it? if i can match resistance readings on a floater arm, and degrees of travel, then i can fairly safely use that aftermarket version, again assuming connectors ling up, i dont want sparks tyvm.

anyways figure ill cut it there, any advice would be greatly appreciated.
 
#7 · (Edited)
I have replaced the fuel pump on my 2001 Echo, so I'll be glad to tell you what I know.

The fuel pump, filter, and sender/float are connected together as an assembly. You are correct in accessing the fuel pump assembly is located under the rear seat/plate. Basically it's constructed around a plastic cylindrical housing, in which the pump hangs in, and connects to the it's regulator/fuel pickup which is connected to the fuel strainer.On the side of the housing is an electrical/conductive surface in which a metal rod will contact (and move up and down) in relation to the level of fuel in the tank via a linkage, the floater keeps that at fuel level to correctly (and hopefully accurately) correspond to the contact point on the sender housing to tell you how much gas is in the tank. Here are a couple links to help you:

http://parts.olathetoyota.com/auto-...e/fuel-system-cat/fuel-system-components-scat

http://ebayapi.loc8apartltd.netdna-cdn.com/00/s/OTYwWDEyODA=/z/1j4AAOSwYaFWfe~i/$_1.JPG





Hope that helps.

*As far as equivalents go, when it comes to components like this (and ignition coils,.mass airflow sensors, o2 sensors, fuel injectors, etc.), there are NONE--STICK WITH DENSO--Trust me on this.
 
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