Thank you for this.

To remove the sender unit, do you just hold the cylindrical portion and rotate counter clockwise?

Yes. Lefty loosey...

10 minutes ago, siteunseen said:

Yes. Lefty loosey...

Sorry, I thought the cylindrical thing was a cover. I was able to get it off. Thank you!

The sender is leaking through the actual unit.

They are notorious for leaking when they get old.  Time for a new one.

ZcarDepot or MSA have them.

Rockauto has them.  Your local auto parts store might too.  Spend a little extra for quality.  I have memories that there are bad ones out there.

https://www.rockauto.com/en/catalog/nissan,1977,280z,2.8l+l6,1209248,electrical-switch+&+relay,oil+pressure+sender+/+switch,4588

https://www.oreillyauto.com/shop/b/lighting---electrical-16777/switches-16486/engine-switches-25047/oil-pressure-sensor-switch-12875/476acd2f2028/1977/nissan/280z?q=oil+sender

Just make sure the plug in is the same. The early ones have a bullet type plug, later is a plastic 2 or 3 way.

I have the sender unit on order and it’s arriving tomorrow. Thank you guys for your help on this one!

 

i want to address the slow leak we are having on the gas tank. We are having a few drops in the circled area. I’m trying to find the cause of the leak but I wasn’t able to see where it’s coming from. I tightened the clamp and it still leaks.

could be pinhole leaks, or leaking from somewhere else and working its way to a low spot.

I pulled my tank and had it professionally cleaned out and sealed. pretty expensive, IIRC he cut it open over the center of the tank to sand blast it clean (no other access) then coated inside.

Other problem areas can be a bad sock or what ever is connected to the pickup tube, holes in the pickup tube sucking air. IIRC it was a franchise "tank re nue" or something like that. No leaks or any other issues since then. I also install a Pre filter, it was a large metal type that was designed to be used in front of the fuel pump.

Cleaning and sealing the tank would be a good move.  I've done a few and had good results.   On the filler hose in your picture, is that moisture on the end by the clamp?  If it's an old hose could it be you just need to replace it?  They do tend to get hard with age and crack on the ends.

Edited April 30, 20195 yr by gwri8

31 minutes ago, gwri8 said:

Cleaning and sealing the tank would be a good move.  I've done a few and had good results.   On the filler hose in your picture, is that moisture on the end by the clamp?  If it's an old hose could it be you just need to replace it?  They do tend to get hard with age and crack on the ends.

Good eye. I looked and I noticed that the filler hose is a little damp. Where would be a good place to find the hose? Thank you!

Before you start searching eBay for a replacement, you probably should inspect the one you have to see if it is the hose or possibly a seam around the fitting on the tank. You might even consider dropping the tank just to inspect the whole thing, inside and out. 

16 hours ago, BayAreaZ650 said:

I have the sender unit on order and it’s arriving tomorrow. Thank you guys for your help on this one!

 

i want to address the slow leak we are having on the gas tank. We are having a few drops in the circled area. I’m trying to find the cause of the leak but I wasn’t able to see where it’s coming from. I tightened the clamp and it still leaks.

Is this picture right side up? If it is, then the filler neck is a real possibility. They can split and have little leaks. They can be a little expensive and rare. That almost looks like a weld bead inside your circled area. Someone may have worked on this already.