Fuel level gauge broken - mech. or elec. problem?

[jaymac]

My fuel level gauge has always been funky, but last week it went off the deep end
Now, as soon as you put anything more than 1/8 tank, the needle shoots up to BEYOND full. It almost disappears off the cluster. Then, it stays there until you get back down to 1/8 tank, and then it slowly makes its' way back down to 1/8. Put in $1.50, and it shoots aaaaaaaall the way back up to "extra-full".
So, my question is this: Is this an electical problem w/ wires or gauges, or a mechanical problem w/ the floating sending unit in the tank. Does anyoe know how/where to get the fix for this problem, depending on the solution?
Thanks,
Jeremy

 

[bullitstang1313]

I had the same problem with mine. Its kind of a mechanical and electrical problem. It has to do with the mechanical sending unit. The sending unit uses a variable resistor to tell how much fuel is in the tank. Usually empty is around 18ohms while full is around 250ohms. I can't remember exactly. Your sending unit probably has a break in the variable resistor which is causing it to give a reading of infinite resistance or extremely full on the gage. You can check this to make sure by using a Fluke, but it sounds like you need to get a new sending unit. I believe 50resto sells them or you can get it directly from ford.

 

[jaymac]

50Resto= $82.
Ouch.
I can always watch my odometer and re-fuel according to mileage until I have $90 to throw away....
bastard

 

[mustangjoe87]

yea, i had the same thing happen to an f150 sending unit or a gallon gas can in the back for when you run out

 

[281pony]

sending unit. common problem, same symptoms.

 

[jaymac]

oh well.
Good to know, I guess!

 

[281pony]

yep, i did see a sending unit from a cheap ebay vendor for just under 50 dollars shipped in my search. i didnt trust the aftermarket piece, so i ended up getting one at ford.

then on top of it, you get the bonus fun of dropping the tank

 

[281pony]

http://cgi.ebay.com/ebaymotors/ws/e...tem=7982989736&category=33557&sspagename=WDVW is a little cheaper

http://cgi.ebay.com/ebaymotors/ws/e...tem=7982141761&category=33556&sspagename=WD1V the aftermarket one

 

[jaymac]

Well, I'm picking up a 190 lph pump anyway, and was going to do it when do my head and intake swap on July 17th ,so maybe I'll ante up for it and do it all together.
This will be my 5th tank drop. It should be a snap (everything "should" always be a snap though, right??)

 

[281pony]

Well, I'm picking up a 190 lph pump anyway, and was going to do it when do my head and intake swap on July 17th ,so maybe I'll ante up for it and do it all together.
This will be my 5th tank drop. It should be a snap (everything "should" always be a snap though, right??)

yeah dropping the tank isint bad as long as your positive how much gas is in there. i "thought" mine was almost empty on the last drop to find half the tank of gas splash down the right side of my body.

that one cheap sending unit "should" work ok. hard to say though, so i went with an oem one. good luck

 

[jaymac]

I think that 2nd leak is just the electrical and holding assembly for the pump, not including the pump itself. It also doesn't include the level sending unit.
The first link is actually the part I need, and I would trust the company, as it's one that advertises in several national Mustang publications, so they should be reputable. $73 is the best price so far by $10, so that's a good option.
Thanks for the link!

 

[281pony]

my bad, i linked the wrong aftermarket one

ill find it, i remember it took me forever to find on ebay.

edit: sorry i dont see the link for it anymore. the title for the pump holder was typed like this: 85-97 FORD MUSTANG SENDING UNIT FUEL GAS TANK 86 87 88" so i just saw that and pasted the link.

its the same seller who has them though, if he puts anymore up.