So apparently my gauge has been broken longer than I thought by searching on here.
so it reads full or over full unti about 1/2 tank, then it starts going down. I suspect if I left it hit 1/2 tank I'd be out of gas. Kids drive so I didn't do too much to fix it.
Fuel pump still seems good, so trying to avoid replacing it until I have to.

If I remember and reread my old post, pulling the anti slosh didn't change the gauge.

So I had my obd2 reader on, decided to add fuel level to see what it says, and it appears to be workingworking. It's been 75mi since filling, and the app shows 88% full, gauge is still pegged over full.

Would the sender be sending 2 different signals? Or suspect something wrong with the dash gauge? Of so what?

 

OBD2 doesn't have a connection to fuel sender in the tank or to the gauge on dash
It estimates fuel used while you drive, so not that reliable.

Anti-slosh module needs to be by-passed, not removed, if that's the problem

What year is the Ranger?

Ford used a Yellow/white stripe wire, usually, to send OHMS to Ground from the Sender(float) in the gas tank to the gauge.
From 1989 and up 16 OHMS at yellow wire on than back of the dash means Tank is empty(float is down all the way).
158 OHMS is Full Tank(float up all the way)

Pull out instrument cluster and find the Yellow wire, I can tell you which one if you tell me the year of Ranger

Then you can use an OHM meter to test Yellow wire, and rock truck back and forth and watch OHMs change as float moves up and down as gas sloshes around.
Anti-slosh module, in the dash, prevents that from happening on the gauge, but you are reading OHMs directly from sender

If the sender is shorted so sends out 160+ OHMS when float is above 1/2 the gauge would stay at/above full until float dropped enough to get past the short.

Sender is like a light dimmer or volume control, resistance(OHMS) change as it is moved one way or the other

 

estimated based on what? How can it estimate 80% full; if it has no idea when it was filled up? [maybe Torque app made some assumption tho]


it's a 99 3.0

So that makes sence; if there's a partial short, it reads full until it drops below the short; but then shouldn't it read right on the dash once below the short? altho I never let the kids go more than about 120mi before filling (19.5gal tank)

 

read here: https://torque-bhp.com/wiki/Fuel_Remaining

And here: https://gmtnation.com/forums/threads...el-gauge.9573/

You fill out vehicle profile and then "tell the APP" when you fill up the tank, it can then estimate remaining gas in the tank based on use


Yes, sender "might" read normally below 1/2 tank, you are there I am not, so up to you to determine that.
Read here on how sender in the tank works: Fuel Tank Sending Unit Tech - FORDification.com

They are not complicated, just a wire on a stick, lol.

 

Thanks for the tips.

So riddle me this.
Took dash apart. Meter on top connector (removed from cluster) touch pin 12, yellow w/white stripe. Shows open, no ohms, no short, open. I tried touching various metal within reach, and pin#2 that best I can tell is a ground.

So that should be empty, like below empty right?

But gauge is reading just under full now.

Took out anti slosh, covered 3 pins, short the other 2, it drops to near empty.
3 pins covered, other 2 normal, it reads 1/2 tank. (Which is my best guess where I am. 99 miles from fill up, 19gal tank)

More thoughts?

I'll do a pump/sender, but would rather not spend $200 right now, esp since it's drivable.

If it helps diagnosis, I started getting lean bank 1 cel a few months ago. Changed o2 again, no change, found a vac line disconnect from fuel pressure regulator (?) That made cel go away for a few days, but now back on, but both banks lean.

Can't find any vac leaks, sprayed 2 cans of carb cleaner and starting fluid all around, no rpm changes.

 

Yes, thats the correct Yellow wire

Dash----------------(yellow/white stripe wire)------------sender--------Ground

So yellow wire is a Ground with variable resistance(ohms)

Set OHM Meter to lowest setting, usually 200
If you Ground OHM Meter and touch other probe to Yellow wire(must be unplugged from cluster) it should read between 16 and 158 ohms always, higher than 158 would mean it is OPEN, no connection to ground
Under say 10 ohms would be short to Ground on yellow wire

Try rocking the truck to get the gas in the tank to slosh around which moves float up and down changing OHMs

 

It reads OPEN, no resistance at all.

Tinker with the anti slosh unit, cover the 3 pegs, it now reads 1/2 tank. Short the other 2 pins, it goes to almost empty.
leave 2 open (normal) and fill up, still reads 1/2 tank.
Tank full again, uncover 3 pins (so back to normal all around) it's pegged over full again like it has been for years.

So I don't suspect the anti slosh anymore =(
I just don't really wanna get in the tank!

but rented a pressure gauge, connected to fuel line; key on (run) engine off, pressure at 0. But it fires right up in a crank or 2; pressure steadily climbs to about 35psi and stays there.
turn off, and it stays ate 35; but over 30min or so it slowly loses pressure, I think it was at 30ish when I put all the tools away.

 

This may or may not be relevant but my dodge had a similar issue. Gauge would read full forever then randomly drop to 1/2 a tank. After it dropped to 1/2 a tank or below it would read normally and go down slowly.

the problem was pretty simple, the float on the sending unit would get stuck everytime I filled the tank. After driving for 100 miles or so it would eventually free itself and drop down instantly. I was able to remove the sending unit and simply clean it up so the float moved freely.

 

Thanks Apex; it's been this way for 3+ years; so I'm thinking it's finally due for an expensive pump & sender unit... =(

 

OPEN means sender or yellow wire to sender is bad


Best way to work on sender or fuel pump is by lifting bed up or off
3 screws, Philips, on filler attachment to bed side
6 bolts in bed, torx-55, 2 front bolts are longer than 2 middle and 2 rear ones
Unplug tail light wiring connector, drivers side rear

Depending on the bumper setup you can often put the rear 2 bed bolts back in, not all the way in, to keep bed from sliding backwards, and then raise the front of the bed up, and hold it up with 2x4s or ??, while you work under it

Dropping the tank is OK if you have a lift and transmission jack
Problem is not "dropping it out", problem is putting it back in and lining it up

 

Thanks, good tips.
I suspect the sender not the wiring since it still moves; just not correctly.

I did drop the 26gal tank on my Expedition, just used a floor jack & some wood. so I think I could get away with it; but everyone says take bed off.

It'll probably be a 1 person job so I'm still undecided.

What other parts should I replace at the same time besides fuel filter?

Guess I just don't understand how it still starts & runs just fine if the pump is weak, esp with no/low pressure at key on?

 

Sender wire should have 16-158 ohms always, so No connection is a bad wire or sender, since needle did move some times then sender or wire has intermittent contact

35psi pressure in a 1999 Ranger is low, should be 55psi
But could be the pressure gauge as well, test it on another vehicle

35psi might show Lean code on a long drive, few hours at highway speeds, but around town it would be fine.

Filler/vent hoses should be inspected closely for cracks, common issue

Dropping the tank on Rangers also means trying to disconnect hoses and wiring in a small space, and then reconnecting as well.

Maybe you can use the floor jack to raise up the bed enough to clear the gas tank and slide it back yourself, put 2x4s under it after lifting to make it slide easier

 

Thanks for all the help, pressure gauge was still brand new so I don't suspect its bad; but I didn't test any of my other cars either; not sure what psi they should be at either...

Guess its from the top then, I'll look around the tank for any leaks too.

any cheaper source for a FF Pump besides rockauto? it's about 1/2-2/3 the price or local box stores; even advanced auto with coupons.

 

3rd party pumps will be cheaper and have a longer warranty than Motorcraft(90 day), but Motorcraft is also $350+

And most 3rd party last longer than a few years but not all, its a roll of the dice

The Motorcraft will last, 15+ years

If you go with 3rd party KEEP the Warranty info


You can look up any vehicles fuel pressure on line

 

The local stores like advance and AutoZone often include a lifetime Warranty. You may pay more there but like Ron said if you keep your receipt at least you have that peace of mind.

 

OK, did the whole pump unit tonight; getting 55 psi, but guage is still stuck on F, should be about 3/4 right now.

Took a meter to the old sending wires & they changed resistance from full to empty. =(
somethng like 170ish to 7 ish
I know it was reading open behind the dash; so where do the wires go between the tank & dash?

 

Its a Yellow/white stripe wire and should run from instrument cluster over to passenger side kick panel and meet up with a Pink/Black stripe wire

The Pink wire comes from Inertia switch, located in that area, it has Fuel pumps 12v power.

And there might be/should be, 2 ground wires, Black and Black/white stripe(black/orange maybe)

These 4 wires run back to the gas tank together, the Black/stripe is the ground for sender

The yellow wire is also spliced in the dash and runs to Pin 12 on the Computer.
And thats in the engine bay, yellow/white wire so same color
If you check OHMs at pin 12 and it's OK then problem will be between splice and gauge