I just purchased a 1995 Q45 Base as a project. It runs and drives, but it has its issues. One of the things not working is the fuel gauge. It reads empty all of the time. I'm wondering if there is anything I can check, like fuses or another component, to see if it's faulty before taking out the fuel pump and looking at the entire assembly.

It also leaks a small amount of gas when the fuel tank is full. I have a feeling the fuel gasket is bad, so I'll be replacing that soon. The tank is about halfway full right now. What's the best way to replace the gasket and move the tank around?

TIA!

You can get the wiring diagram for the fuel sender here on page EL-38:
https://www.nicoclub.com/service-manual ... 5%2Fel.pdf

It's a pretty simple-minded circuit. You should see a voltage at the Purple/Yellow wire at the cluster with the tank connector loose, if not the gauge is bad. You should then see the same voltage at the tank connector, if not the P/Y wire is open. If so, jump P/Y to Black at the tank connector, the gauge should peg to full. If so the sender is bad, if not the Black ground wire is bad.

jcas wrote: ↑

Mon Jun 19, 2023 8:25 pm

It also leaks a small amount of gas when the fuel tank is full. I have a feeling the fuel gasket is bad, so I'll be replacing that soon. The tank is about halfway full right now. What's the best way to replace the gasket and move the tank around?

to NICO!

The fuel tank sending unit (that includes the pump and float for the fuel gauge) is accessible by removing the back seat and package tray. You don't need to remove the fuel tank, and probably don't want to mess with that unless there's some other reason to take it out. If you haven't downloaded your factory service manual, they're available at www.infinitiservicemanual.com

Here's a very detailed old thread that I wish had pictures. It probably did at some point. fuel-pump-replacement-t6268.html

Q451990 wrote: ↑

Wed Jun 21, 2023 10:42 am

jcas wrote: ↑

Mon Jun 19, 2023 8:25 pm

It also leaks a small amount of gas when the fuel tank is full. I have a feeling the fuel gasket is bad, so I'll be replacing that soon. The tank is about halfway full right now. What's the best way to replace the gasket and move the tank around?

to NICO!

The fuel tank sending unit (that includes the pump and float for the fuel gauge) is accessible by removing the back seat and package tray. You don't need to remove the fuel tank, and probably don't want to mess with that unless there's some other reason to take it out. If you haven't downloaded your factory service manual, they're available at www.infinitiservicemanual.com

Here's a very detailed old thread that I wish had pictures. It probably did at some point. fuel-pump-replacement-t6268.html

Thank you! I was thinking of moving the tank around because the previous owner didn't bother fixing the fuel tank issue and there is a strong odor of gas in the trunk that I would like to clean. It would be easier to clean if I could move the tank around a bit.

Jcas-My 95 Q45 failed smog for evap, which means there is a vapor leak. The fuel pump assembly has a o-ring seal, but my fuel pump assembly wouldn't seal, even with a new o-ring. I fixed the issue by making a gasket out of 1/16" Buna-N nitrile gasket material, I used gray RTV to adhere the gasket (you can use liquid spray gasket/adhesive as well). I replaced the original screws with M5 metric hex head screws that were slightly longer (10mm), along with lock and flat washers. That fixed the leak.

The sending unit can be tested with a multimeter, once you get the pump assembly out of the tank. It's in the FSM, section/page EL-41 (BTW, EL-39 is the troubleshooting tree for the fuel gauge) At full tank, pin G(+) and pin E(-) should read around 5 ohms, at empty it should read 80-82 ohms. It's a relatively flimsy contraption, it's easy to damage when inserting the pump assembly back in the tank. The float "leg" has to go in first, then you angle the pump assembly in. Also, the pump assembly has to be indexed so the sending unit float at the 3 o'clock position if you're looking at the tank from the back of the trunk looking forward. Last thing, I left the o-ring in place and the gasket on top. Hope this helps.