Long Shot
 

I know we don't have many rotary guys on here (and the ones we do have are on the other rotary sites and have probably already seen my post), but I was hoping maybe one of the mechanics on here could lend me a hand.

My fuel gauge (1983 GSL mazda RX7) is broken. It says that I have 3/4-full tank of gas all the time. This is not the case (as a friend and I found out a couple weekends ago on the highway). Other than the sender unit, the wiring the gauge body or the gauge itself, is there anything else that could cause this? Also, what is the easiest route to take to test for each of these. I can't take it to a shop as I'm in the midst of moving out and am extremely strapped for cash.

Suggestions? Has anyone else had this problem and fixed it? I looked on rx7club.com, found the FSM and am currently going through it, but I'm hoping someone can help me out.

TIA!

I think you've basically named everything that can go wrong. My guess would be to first check the gauge to make sure nothing is sticking and possibly even temporarily swap in another cluster if someone has a spare kicking around. Just to try to rule that out first. It's relatively quick, easy, and the cheapest fix. If that doesn't solve it, drop the tank (or access it through the hole in the body, if the FB's have that ability) and swap in a new sender. Even if that's not the issue, it's always good to replace them every few years.

A friend of mine is coming out next week to re-ground the tank. He's convinced that's the problem because his did the same thing. But the thing is, now the oil pressure isn't sensing properly either. So Morgan thinks it might be the sending units (whereas I think it's the gauge cluster). So I guess I'll just have him look at everything when he comes out (make his time worthwhile). But I'll definitely ask him about the fuel sender unit. Thanks Lomac =]

The only reason why I suggest the sending unit is because after a bit of urban 4x4'ing last night (don't ask), we bashed the tail-end of my buddy's truck pretty hard, knocking some of the connections on the sending unit loose. We only noticed it when the fuel gauge needle stopped moving. A big V8 truck couldn't be getting that good of a fuel mileage. :lol

Hahahaha probably not. Morgan said the same thing as you, so I'll get him to check. :D