Late model fuel tank drivers side stays full

[diesekte]

I've got a late model that started dying on me with fuel gauge still reading as me having some fuel. This has happened two or three times. When I opened the port holes and took the senders/pump out, the driver's side is always full while the pass/pump side is empty, and I can only fit ~8-9 gallons in when filling up afterwards. There is very minimal rust, tank isn't dented at all, and all lines seem clear after probing them with a wire coat hanger/blowing air through. Am I missing something here? I thought the "jet siphon" tube was the issue but it appears to not be clogged.
Usually these topics are about early models, I don't see much on lates.
I've replaced the pump as well and still have the same issue - I went from a 255lph to a stock pump and no difference.

[jlevie]

That suggests that the siphon isn't working. That could be from insufficient flow in the return line (like from a worn pump, clogged filter, or obstructed return line), but since you changed the pump it can be eliminated as a suspect. And an obstructed return line normally causes other problems. You can pump the fuel out of the left side, pull the return line (plug the tank nipple) and check the flow.

But my guess is that the siphon is bad and the only fix for that is to replace the tank.

[TobyB]

...or stick a secondary pump in the driver's side. Not trivial, but entertaining...

I agree, sounds like the 'jet pump' isn't pumping.

t

[diesekte]

I haven't found any evidence of someone having this issue and then being able to solve it without just getting a new tank. Is it possible to unclog/rehab the jet pump or is a new tank the only answer?

[jlevie]

On an E30 the siphon is an integral part of the tank. Which means that replacing the tank is the only option.

[diesekte]

Any recs on replacements? New oem is out of my budget, so it's ebay, rockauto, or oreilly/autozone for me

[Gregs///M]

A poorly grounded fuel gauge is very common. Try tightening the 7mm nut behind the gauge and you may find that needle drops to its correct position.

When the fuel or temp gauges read max, that means they have poor grounding.