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Topic: Fuel sender and gauges.... confused! (Read 2614 times) previous topic - next topic

Fuel sender and gauges.... confused!

Ok, so I finally got my SN 95 gauge cluster wired into the 04 dash I swapped into my 88 TC.  Problem is the resistances of the fuel level sender are different and backward (i think) on my TC from what I need for the mustang gauge.  Everyone seemed to tell me to just get a fox mustang or thunderbird sport sender (same piece) and it should be fine (because it's already known that the gauge works fine when swapped into a fox mustang).  So, anyway, $140 later I have a box full of "fuel tank sending unit" parts for an 88 sport and there are NO electronics.  It seems to want me to use my original float mechanism but I'm assuming this is where the variable resistor is.  So this doesn't help me what-so-ever.  What is the part I actually need to get the proper resistances?!?  Anyway, here's what I got as a fuel tank sending unit from Autozoo:
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Fuel sender and gauges.... confused!

Reply #1 –
Did you test the new sender to see it it read opposite of the other one?
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Fuel sender and gauges.... confused!

Reply #2 –
:rollin:
cool
looks like auto zone sold you the fuel pump housing assembly.  nice looking kit btw but was it really that much?

your sender will be a float on a metal rod  """""CALIBRATED"""""" at a bent angle.  all of this stuff terminates to a mounting bracket on the tank similar to the fuel pump.  Yes, that is were the variable resistor is and its windings are exposed to the fuel.  Dono why i said that but its always bugged me.

trust me,, dont let any kids mess with it.  My kids were found playing with mine and beating on each other just goofing around.  Now the tank reading is off too much.

as for your issue I can assume a couple of things.

in your cluster you have an IVR
in your tank you have a sender with float and variable resistor built in.

so,,im not sure what your missing,, unless your dealing with a tank that has no fuel level sender.

BTW, My EVTM has opposite resistance readings such as what the reading is when full vs empty.  The shop manual is also bass akwards.  Ive never measured the resistance but someone has im sure.  Anyway, if you have a float,, and a cluster with the IVR, you should be good to go.  My DIY link has the information dospoogeented for how much they should read so take a look see in there.

Now go get your money back.

Fuel sender and gauges.... confused!

Reply #3 –
Yeah, well, I knew it was wrong when they showed me the pic but they insisted so I figured I'd check it out.  And yes, it was that much...  Anyway, the problem is, even rock auto shows the EXACT same parts as a "fuel tank sending unit" so idk what to order next!

And you're right, Scott, the resistances are backward from a TC to a sport/mustang.  so what I really need is that variable resistor (or the unit it's housed in - my current float/arm should be fine).
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Fuel sender and gauges.... confused!

Reply #4 –
Thats gotta really suck. I cant think of anything that would help.  I never had to order one.

You may want to consider seeing if vinnie can get you one.


Has anyone here ever had to buy a sender for the tank?
Lets help this guy out,, gezz, look at all the stuff he's done to this point.

Fuel sender and gauges.... confused!

Reply #5 –
LOL, thanks Scott.  I just can't believe it's this complicated.  And the fact that they sell all these parts (the ones I just got) and there really nothing to ever go bad on them yet the part with actual electrical components can't be found anywhere!

I am considering a trip to the JY tomorrow (even though it's 1.5 hrs of driving with gas at $4.50) for a bunch of stuff...  perhaps I can get myself to drop a mustang tank and get these parts.
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Fuel sender and gauges.... confused!

Reply #6 –
bust....  all the yards had the tanks pulled....  one had the senders on a shelf, but not marked and probably banged out of calibration.  anyone else have any ideas?  how about someone parting a 5.0 'bird?  I know that unit would work...
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Fuel sender and gauges.... confused!

Reply #7 –
Another question:  is there a separate unit bolted into the tank for the fuel level sender?  Meaning, the float and resistor are located in different parts of the tank?  I ask because I see the fuel pump hanger listed as a "fuel tank sending unit" and a resistor/float unit as a "fuel sending unit."  Both have a circular mount and only TWO wires (so I'm thinking obviously they are not combine)...  anyway, can anyone look up part numbers and compare 88 mustang to 88 thunderbird sport?  If these are also the same part I can get one from eBay...  thanks!
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Fuel sender and gauges.... confused!

Reply #8 –
Booksix,

I am working on a very similar issue. I have tracked down what I need, now I just have to perform some sorcery and testing. Once that is done in the next couple of days, I will have a good piece of information (including some pat numbers) on what can be done for these obsolete fuel level sender issues and I think everyone will find it cheaper, easier, less of a head ache.

Stay tuned! You will see the post when I am ready and I will also post here so you know that the info is posted.

Michael

Fuel sender and gauges.... confused!

Reply #9 –
I'm thinking of putting the star-wars tach gauge where my voltmeter is (where the TC ride control switches go) but I have the stock gauges and sender and of course the star-wars one uses a different sender that reads the opposite way. I did some bench testing and I think I've established the proper voltage reading to send to its fuel level input to make it read empty or full. I'm considering getting an buttstuffog microcontroller that I can program to convert the base sender voltage to the star-wars one. I would have to get one that has an ADC and a DAC, and I haven't yet built the courage to try this, but I think it's theoretically possible. Purely in theory, it *should* be possible to recalibrate any sender to any gauge with the right program.
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5.0L Speed density
Explorer intake
'92 Mustang GT cam
GT-40 racing heads
Unequal length headers
Custom-made duals
19# injectors
65mm TB
AFPR
T/C header panel
11" brake upgrade
T/C rear sway bar
Electrical mods: too many to list :D

Fuel sender and gauges.... confused!

Reply #10 –
Quote from: Quietleaf;222691
I'm thinking of putting the star-wars tach gauge where my voltmeter is (where the TC ride control switches go) but I have the stock gauges and sender and of course the star-wars one uses a different sender that reads the opposite way. I did some bench testing and I think I've established the proper voltage reading to send to its fuel level input to make it read empty or full. I'm considering getting an buttstuffog microcontroller that I can program to convert the base sender voltage to the star-wars one. I would have to get one that has an ADC and a DAC, and I haven't yet built the courage to try this, but I think it's theoretically possible. Purely in theory, it *should* be possible to recalibrate any sender to any gauge with the right program.


Interesting idea. It conceivably could be done. Although I had thought of making an inversion circuit with progressive resistance to solve my fuel sender dilema, it has seemed like too much trouble at this time. Maybe something I might try another time.

Fuel sender and gauges.... confused!

Reply #11 –
Well I ordered an ADuC7020 development kit and buttstuffog microcontroller, and I have *extensive* programming experience (including some embedded work) so I'll see how this turns out. I'm not an electrical engineer, but I had a year of electronics in college. When I get the kit I'll go get the dev tools and see what I can accomplish.
[SIGPIC][/SIGPIC]
5.0L Speed density
Explorer intake
'92 Mustang GT cam
GT-40 racing heads
Unequal length headers
Custom-made duals
19# injectors
65mm TB
AFPR
T/C header panel
11" brake upgrade
T/C rear sway bar
Electrical mods: too many to list :D

Fuel sender and gauges.... confused!

Reply #12 –
Quote from: Quietleaf;222695
Well I ordered an ADuC7020 development kit and buttstuffog microcontroller, and I have *extensive* programming experience (including some embedded work) so I'll see how this turns out. I'm not an electrical engineer, but I had a year of electronics in college. When I get the kit I'll go get the dev tools and see what I can accomplish.


Please keep me posted!
 

Fuel sender and gauges.... confused!

Reply #13 –
the tank has two round devices. (actually three,, there is a small grommet for emissions which a vac hose leads up to the charcoal canister)

one is for the fuel pump hanger (contains fuel pump ect)

one is for the fuel level float (contains the variable resistor and float)
the ones you saw on the shelf probably had the resistor on them and its likely they are not all fuggered up like you think.  I do not know the angle at which the metal rod needs bent to in order to make the empy read correct. 

However.,,,,,,
If you get one, set it in the tank.  reach in the fuel pump hole if you can and feel if the float is touching the bottom.  If its off the bottom , swing it all the way up and see if it hits the top of the tank.

If the fuel level / sender arm clears both the bottom and the top about equally, then its probably ok.

just verify the resistance with a meter and test it like you would a tps.

the gap you have between full and when the needle starts to drop would represent the delay in the tank dropping from F like we all often experience.