Guys, I will attach a picture for reference. I just installed a used set of gauges on my RHD FD3S. Everything works as I have test except the fuel gauge is showing way past full. I pretty much have a full tank as I filled it up yesterday and it was working fine with my old gauges. But when connecting this set of gauges it made the fuel needed go past full. Any idea why?

 

Not sure why it would be reading so high, has the cluster been disassembled previously? Might be that the needle and motor are turned out of alignment.

The easiest way to test is to get access to your fuel pump assembly and unplug it. Turn the ignition back on and see where the needle drops down to for "empty"

 

Could be a bent floater on the pump, but I'd imagine it would be awfully bent to be that far off. Does it go down as you burn through fuel?

I dropped my pump assembly once and slightly bent the float hanger and it showed slightly under full on a fresh tank.

 

Only change was I swapped gauges, previous gauge worked 100% correctly. Than added this RE Amemiya gauge and it did this.

 

Japanese volts dude

 

This is most likely a calibration issue, i.e., the new gauge is not calibrated for or designed to use the existing fuel level sender in the tank.

 

That is a factory Mazda cluster from the 97 Type RS-R. As noted on the tach, it was a special trim for the 30th anniversary of the RE, rotary engine.

 

You think they used different gas level sensors or something?

 

How would I go about calibrating it you think?

 

How would I go about calibrating it you think?

 

I don't think this is a calibration issue, but look at RE 30th Anniversary cluster see if anyone ever mention the need of calibrating the fuel gauge. My guess is it's a ground issue, mine did that when I had issue with the little ground wire at the hanger. Mine would real over full or way below empty, until I re-seat the ground wire and the gauge went back to normal. Not saying your issue is at the hanger since you didn't do any work there, but double check your connection behind the cluster.

 

probably the needle was removed and reinstalled out of alignment at some point is my guess

 

Does the RE 30th anniversary cluster fuel gauge that the OP installed use the same fuel level sender and wiring as the OP has in his tank? Unless we know that for certain, calibration is still on the table. That said, I'm guessing Mazda retained a common fuel level sender with the RE 30th gauges so that makes calibration issues less likely. I'd check for bad grounds behind the cluster or tank hanger.

There's a good troubleshooting guide/procedure for the fuel gauge in the additional Body Electrical Troubleshooting FSM that Dale linked in another post... If the OP doesn't have that file, I'd suggest he download it and start from there.

 

It'll be weird for Mazda to make 500 of these cluster that required a new level sender to go with it, I think the cluster is likely just a facial change with all the electronic remain the same, but anything could happen.

Maybe ask Rich, paging Goodfella
https://www.rx7club.com/build-thread...1029939/page7/

 

My vote is a shorted signal lead, or bad gauge cluster with the same issue. It is simple enough to eliminate the sender from the equation, unplug it and see what happens. My feeling is that the problem is not at the sender (or the sender calibration), it would not make any sense from a cost perspective to have a special part number for one model variation.

 

If you unplug the sender it'll got way below E, or should be.

 

Just posted this in another thread.

I believe the stock fuel gauge is "hard set" to work with the OEM sender unit, meaning you can't calibrate it. Simply gently pull the needle off and place it back on in the "full" position. That should do the job.

If you want to check if the sender unit is correct, you can measure the ohms it is producing. If the tank is full, the sender unit should read 6 ohms. Empty = 80 ohms.

So, if it reads 6 ohms at full, then you can try resetting your needle to the full mark.

It is possible the new gauge has a different ohm range than the stock FD unit, but I doubt Mazda would do that.

 

Great timing of this thread. Mine reads 3/4 when full. It’s pretty annoying. Add this to the todo list

 

Any chance your sender float has some fuel saturation, i.e. is "heavy"?

 

^ You can test this by using an ohm reader on the sender wire per the range detailed in what I posted.

 

I think this is outlined in the Body Electrical Manual that I just posted a link to.

I seem to remember the 99 spec gauges had to have an additional ground wire to work, I don't know if it's the same case here since this one doesn't have a boost gauge. may be worth reading up on running a 99 cluster with the boost gauge.

Dale

 

Reach out to Michael Gagne on the Facebook groups. He just did work on my 30th AE cluster. Part of his process is a full diagnosis which would pinpoint the issue here. He replaced any copacitors that may cause an issue in the future, plus he switched my odo to miles and calibrated my spedo to mph. He also noted that my tach was within Mazda spec, but he was able to calibrate that a bit closer to true as well.

I believe David is correct, and all that really needs done is the needle needs to be adjusted. But having miles and mph plus the piece of mind that it should last another 30years now is well worth the price he charges. His turn around time is fantastic as well (it should be noted, my cluster did sit in Canadian customers for almost a week...nothing he can do about that. But he had my cluster diagnosed, fixed, calibrated, and shipped back out in under 24 hours from the time he actually received it)

 

^ That would be well worth the time and money. That way you know everything is in top working condition.

 

Thanks, any chance you know the link? If not I'll look for it. Thanks.

 

Wow thanks for the info, do you have a link to connect me with him? There are a couple USA options I've seen people recommend for gauge repairs.