Fuel pump float sticking?

[Cadeez]

I filled up today, and when I turned my car on to leave the needle only rose to half tank. This happened once before, except the needle didn't rise at all. Once I turn the car off, then start it back up, needle rises to full normally. Could this just be a lazy fuel pump float? This car sat for ~5 years prior to my purchasing it, maybe there is some old gas that gunked it up? Would something like Seafoam remedy this?

[ELCID86]

Mine is similar but it usually takes an hour or so to move all the way to full. I swapped pumps and my cluster and it's still the same. I'm thinking it's a voltage issue, but I don't know where the issue could be.

I don't know how seafoam could help.

[Cadeez]

Well shoot, hope that's not the case with mine. It's only happened twice, not a huge deal. I was thinking if there's a chance that the float arm on the fuel pump itself was sticking, that seafoam in the tank might clean it up.

[ELCID86]

The pump/float is pretty easy to pull out and inspect. What's your mileage? OE pump? Maybe swap it out?

[TheFinanceGuy]

I'd swap the pump if it is original anyway.

[Dave1027]

I'd swap the pump if it is original anyway.

+1

[Johnmadd]

Could be a ground issue possibly.

[Cadeez]

Just turned 95k, can't imagine the fuel pump goes bad under 100k miles? But as I said, the car was sitting for years, the PO (who is a BMW tech) said he did all of the standard maint for getting it up and running again. But I have a feeling i'll run into little bugs like this now and then. It only happens right after fill up, and it's only happened twice. Totally fine now. Fuel pump is relatively easy to get to and remove, so I may pull it out and inspect it at some point

[ELCID86]

Take the advice about replacing it or at least keeping one in the trunk...


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"ZHP is a garbage option anyway- just some cosmetic upgrades with a different cam and diff to claw back some of the performance lost fitting those hideous and heavy wheels. Any 330 with a 3.46 diff will smoke a ZHP every time. The whole Mafia thing reeks of childish behavior." - anonymous E46 fanatic

[Cadeez]

That might be a bit overkill... Car has no issue getting fuel, it runs great and pulls very smoothly all the way through the rpm range. $150 isn't in my realm of "just in case" parts. I'll keep an eye on it and if things change I can go from there