Had my fuel sending unit replaced and did the fuel pump for good measure while the tank was out. The video at the end of this post by someone named Rick S. provides an impressively detailed analysis of the issue. The short version of my story being that I recognized a number of the symptoms he described have been going on with my truck for years. Recently it started reading 1/4 tank low all the time. I'm keeping this truck forever so I fixed it and wanted to provide some pics and info.
For reference, my 4R is an '07 V6 with ~228K miles.
Cost: Parts ~$283 | Labor $393 with 10% veteran discount makes the total ~$676. Yeah, a lot of money, but probably about a month's car payment on a new vehicle so there's that. Someone comfortable doing the job themselves could do it for about $250 worth of parts (fuel pump kit, fuel sending unit, and the housing with the filter media and even that's kind of optional).
Chokes me to pay the labor but after consideration of the job itself and other things going on, it was worth it.
OEM items are from Toyota's online store. Shop around by clicking the dealer names if there are multiple dealers in your area as some offer significant discounts. Parts:
8332060440 $ 95.70 GAGE ASSEMBLY, FUEL SENDER
2330050120 $ 37.97 Fuel Filter << This is the housing w/filter media in it
7714435010 $ 33.59 Fuel Tank Lock Ring << Didn't necessarily need
7716904050 $ 6.34 Fuel Pump Tank Seal << Gasket
Denso fuel pump & mounting kit - ~$109 from Amazon
Here's a comparison of the fuel sending units and the problem is obvious - the "track" of contacts where the pin or whatever it is moves up and down gets worn away over time.
What it's supposed to look like:
What it actually looked like after removal:
Interestingly, the 4th Gen fuel filter has two components. There's the strainer, which I have to say looked pretty clean for the age and mileage.
Old:
New:
Then the housing itself has filter media inside, visible through the hose connections in this pic of the new one. I unfortunately couldn't get a pic of the old one but it was nearly black.
Here's the video by Rick S. Worth watching if you're having these issues or just want a
very thorough understanding of the fuel sending unit and how it works.
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