Scrappy_Brap

Hello, I'm working on my 84 gsl and I've had some issues getting the fuel gauge to work, the fuel gauge only reads empty and I've owned the car for a while now and I'm just now getting around to fixing it now that I'm going turbo I can't play "guess how much fuel is in the tank". One time it randomly started working for a day and then stopped randomly. I've had a couple of small wiring issues in the drivers side bin due to mice chewing on the wires (I've found 3 dead mice so far and I'm still counting)

I've pulled the tank to see if I could remove the sending unit to inspect it but the screws are rusted to the point where you can't even get a screwdriver in to turn it.

If anyone would have some insight on this it'd be highly appreciated!

Scrappy_Brap

Also I pulled the pickup out of the tank, I see two hardlines that run to the bottom of the tank and one that ends right at the top of the pickup (so it exits at the top of the tank) are the two hardlines sending and return lines? Or am I wrong

Toruki

It depends on the year of your car for the specific sender config.

From what I've read, the first thing to do is to make sure you have a really good ground to the sender unit. The other big caveat is that the sender attachment screws are prone to stripping. Not sure if that's the threads or heads (mine came out/went in easily) but it is best to be super careful when reinstalling them.

I have an '83 FB and the resistance of the sender ranges from 0 to ~110 Ω with 0 Ω at full. To test the sender, remove it as you have done and stick an ohm meter on the terminals, it should read smoothly increasing/decreasing without jumps or dips in value as you "exercise" the sender.

If the sender is okay, it might be the gauge. If both the temp gauge and the fuel gauge are dead then it could be the voltage regulator on the instrument cluster---so says the forum.

If just the fuel gauge, you can test it by disconnecting the plug from the sender, and placing a known resistance from that 0 to 110 Ω range and see if the gauge behaves accordingly. Note that 55 Ω is not = 1/2 full. It's a bit non linear.


OK< instead of writing all of that, I should stand on the shoulders of my ancestors and link you this (which is where I got all of my info anyway

https://www.rx7club.com/1st-generati...orking-782186/

Toruki

So in the fuel gauge thread noted in my post just above, tg mentions the grounding strap. I needed to check mine, so here's a shot of where you should be finding it intact.

Scrappy_Brap

Hmm, I'm not sure if I've ever seen that grounding strap, where does the other end of it run to?

Toruki

Better(?!) photo. However, I think as long as you connect to the specific muffler bolt to the frame *someplace* good, then that should achieve the intended effect. You could test with a jumper to find a good spot.

Scrappy_Brap

I'm definety going to give it a try, thanks I highly appreciate it! Ill keep you guys updated

t_g_farrell

iTrader: (1)

Actually I was not just referring to the strap but to the sender getting grounded to the
tank. You see the sender carries ground to the variable resister through its housing
that also fastest it to the sender cover. The cover gets its ground via the screws holding
it to the tank. Over time that connection goes bad.

DivinDriver

iTrader: (15)

The exhaust ground strap has nothing to do with fuel tank ground. But the concept of checking grounds is valid.