Fuel Level Sending Unit Ohm Range

KenF

KenF

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While I have the fuel tanks out (that was fun!) to get boiled out, I was checking the fuel tank level sending unit. Arm was stuck but was able to free it up with some penetrating oil and lots of moving it back and forth. Looked inside at the coil and arm, and it seems okay. Ohm range is 16 at full, 239 at empty. Is that the correct range for an accurate fuel gauge? Thanks.
 
Readings from 1978

There is a good article about the fuel gauge sending unit and the resistance at different levels. Check out http://www.tigersunited.com/techtips/BrennanGauge/rt-BrennanGauge2.asp. You will see that the author measured 145 ohms at 2 gallons and 21 ohms at 11 gallons. He made these measurements back in 1978 on his Mk IA. Others might have taken measurements on their cars and come up with something different.
 
What's dis thang

Ohm meter....
I've taken two apart cleaned the wiper contact and then the wire windings with contact cleaner removing all corrosion. Do this by peeling back the little tabs as I recall to expose them.

Two other cars I had my mits on worked without doing anything.
You are a brave guy taking on the tanks. I only know they are hard to take apart and probably 5 times harder to get back together.
I don't know why they are epoxy coated inside when most gas tanks of the period are just bare metal. Did your service remove the epoxy? In the motorcycle word everyone almost always turns up their nose at a gas tank that has been epoxied. My driver has Re Nu product in it done in 1999.

More fun in store for you just wait until you go and try to put the Hayes device
into the gas filler....
Maybe you have the same problem with the Stang....
.
 
Okay, thanks, I think my sender unit should be good to go.

Factory inside epoxy coating? They must have skipped mine. :)

Did read a few other threads about to coat, or not to coat. Kind of leaning towards a good cleaning and just keeping the tanks full of that good ol' crappy California gas. Heard bad stories about flaking, etc., of various coatings, although there may be newer products out now. Maybe when I get them back I'll slosh a bit of Ospho inside to keep the flash rust off.

IMG_4523.JPG

Yeah, reinstalling these puppies ain't going to be fun.
 
The Good Stuff

Marine grade (military) fuel tank coatings are more than likely not available in many E.P.A. enslaved States.
 
A good idea when they are back is to insert some chain or nuts and bolts with fluid and give them a good rattle and again. So any corrosion on the bare tanks will be removed before fitting
 
Additives

Stabil and a little 2 stroke oil for easing back to life is helpful. The top oiling of cylinders hand turning although my bud's tell me, "you'll never turn the motor over fast enough to run oil pump." Suggestion was for the Distributor pull and priming with hex head shaft like on new motor. I've got one and it had a under 10 dollar price tag on it but its 20 years old.

As for the tanks if I had a dollar for every time I read a motorcycle gas tank cleaning ? on my motorcycle forum, I could pay Sunbeam Specialties. I have done nearly all methods looks like a Evaporust product may do your as it concentrated near bottom of the tank. A SAOCA member used some high strength toilet bowl cleaner and that's a new one to me.

Look closely at the expansion tank they can have micro fractures along the sides near any scoring marks from the mfg. process or PO putting on 22 lb cap. The hold down bolts are just a little too short and the clamp is poorly designed and needs trimming to be able to close completely without hitting nib on clamp. Better yet pressure test it before installation with loaner tool from the auto parts store, the same goes for heater core. Wish I would have taken my own advice.....
 
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