KahnBB6

iTrader: (5)

So I got tired of my SC300's fuel gauge reading inaccurately: when topping off, it will go nearly to F and when at 3/4 tank it reads as 1/2 full. When 1/2 full it reads as 1/4 full and never goes below that (and I've never had the courage to test the car's fuel capacity when the gauge is at 1/4).

I have purchased a new stock factory sending unit that goes into the fuel tank (Toyota Part #83320-80210 "GAGE ASSY,FUEL SENDER"). I want to put this in and it certainly looks like it would be easy do to but I'd like to follow a guide if anyone knows of one. I have searched but haven't found anything.

I've read that this can also be the sign of bad capacitors in the gauge cluster but I wanted to try this first since I have maintenance records from Lexus indicating that the whole cluster was replaced once around 100k miles (I am now at 192k). All my other gauges are fine. This is also with an original 5-speed cluster.

So is it as simple as this?

1) Disconnect battery
2) Remove trunk liner
3) unplug fuel pump and sender connections from the fuel tank
4) remove all the nuts holding the fuel pump and sender in place
5) remove fuel pump and sender section
6) swap fuel pump onto new sending unit assembly (do not know how I should do this without inadvertently breaking something)
7) Reassemble in reverse procedure

And would I want to have my fuel tank 1/2 full or less?

I've searched all over the forums and haven't turned up much in the form of a guide for this. I'd appreciate any advice you guys would have to get it done correctly.

Thanks!

O. L. T.

iTrader: (17)

it''s gravy. don't sweat it. Just do it. Very straightforward.

KahnBB6

iTrader: (5)

I'm glad to hear that! So does my very abbreviated series of steps look correct to you? Is there anything I am leaving out? And I am assuming that doing this with 1/2 tank of gas is mandatory?

KahnBB6

iTrader: (5)

You were right. It was very easy to do! I disconnected my battery, removed all the trunk liners and put down newspaper and the factory spare tire donut to catch any excess fuel.

I am pretty sure I changed out the sending unit with 3/4 of a tank of gas, in case anyone else is wondering about that. Be forewarned: my fuel gauge was off in guesstimating that reading... but I am pretty sure I am right. 3/4 tank is okay to do this.

The rest went very easily. You need an 8mm socket wrench fitting or a regular 8mm wrench to remove the bolts around the sending unit. The subwoofer magnet is in the way, so the wrench is mandatory for the upper bolts. Just carefully disconnect everything and get the wires out of the way. I used a strip of 2" thick black "gaffers tape" and stuck it against the trunk rubber seal (gaffer's tape is the greatest single temporary and reusable adhesive tape in the world!). The new sender from Toyota should come with a set of new bolts with fresh crush washers attached. Use them, since this is a critical part of sealing your car's fuel system and you don't want to be using 17 year old bolts if you can help it.

Unfortunately for me, when everything went together and I turned the engine on, the fuel gauge is still reading the same as before, so I think I have the dreaded gauge cluster issue even though my records from Lexus state the cluster was replaced once already at a dealer several years ago.

Anyway, this install was as easy as O.L.T. said it was. If you're mechanically inclined, careful and prepared it's a piece of cake.