So I need to replace mine and am wondering what you guys are doing about replacements?
Thanks

 

The only thing you can do is have your old one rebuilt. I sent mine to the sending unit guy, they are located in ny. They restore sending units and build custom ones. Mine has been working great since I got it back about a year ago now. I'm pretty sure it was$165 for them to restore it. As for my gas tank I sent it to my local radiator shop and they cleaned it and put a liner inside it and coated it in a rust proof coating outside and that was $250. This is all on my 80.

 

I have a thread in the archives that shows how to use the electrical element out of an FB sender (easier to find) to restore the SA sender. Goes back to around '09, I guess.

Edit: Link ---> https://www.rx7club.com/1st-gen-arch...sender-786986/

 

I'll post a pic tomorrow but mine looks like hell. Rusty and nasty.
Thanks

 

What are the ohms (empty and full) for the sending unit?

 

That's another reason I sent mine off they'll fix it no matter the condition. Though it is a bit pricy but worth it I thing,I hate running out of gas on the hwy lol

 

So where did you send it?
Thanks

 

Google www.tristarrradiator.com or you can email him at sendingunitguy@gmail.com my total was 157. But 12 of that was return shipping, if I ever needed another one done I would definitely let them do it.

 

Cool- guy quoted up to $175. Not horrible.

 

Fixing it yourself would cost you around $15-20 for a used FB sensor & an afternoon's work. Whether that's better or worse to you is a personal choice.

 

These things are pretty damn simple. Unless the wires around the rheostat (not sure if thats the
right name) or the pickup are physically broken. A good cleaning, some adjusting and its good
to go. Also make sure the float is air tight and actually floats. One issue is the ground from the
in tank sender to the tank. It goes via the attachment of the sender plate. If thats bad you can
put a wire from the send peice as it comes through the plate and attach it under one of the
mounting screws to get good ground.

The ohm range is documented in the FSM.

 

Mine was actually broke, I forgot to unplug it while pulling the tank and when the tank fell it broke the connector off. So I just said ahh screw off they can fix it more power to them lol

 

hmmm, I didn't ground mine when I checked it so I need to do that... May be it works..

 

I can ship you a fuel gauge for $20...
getting rid of my old fuel tank. It works fine before I put a fuel cell in my rx7

 

anyone know how to adjust an aftermarket fuel float to read properly on the rx7 fuel gauge? for some reason it reads backwards, irregardless of where I put the ground / connecting wire.

Full = Empty and Empty = Full on my gauge.

I was thinking I had to open the dash cluster and reverse the connectivity wires on the gauge maybe? but not sure if there's a simpler fix.

 

The gauge doesn't read a value from the sender, its not digital. Its based on the resistance
values. Your new sender is the opposite and I don't think any switching of the wires will help.
I could be wrong. Got any more specs on the new float assembly?

 

Damn, I wish I would have seen this before I gave the go ahead to rebuild mine!
Thanks anyway though!

 

You are right - resistance is non-polar. Only way to fix this would be to physically rotate the resistor element in the new sender end-for-end - - if possible.

 

I have a handful of 1st gens "laying around" in my shop (lol)

I tested everything from 79-85 all different models and they all gave me the same readings

Directly at the fuel level sending unit:

Full = 6 ohms
1/2 =31.5 ohms
Empty = 80 ohms

This is usually backwards from what logic or any other car manufacturer would use in other cars (Aftermarket sensor causing Arcolithe's gauge to read full when empty and empty when full). Even the 88 TurboII in my shop has the exact same readings. Maybe you could make the newer sending units work with a little ingenuity. If you are having yours custom made, tell them 70 ohms for the empty reading so when your gauge shows empty you really have 1 gallon left (saves you from having to push your car if you run it down to fumes )