Just wondering if any of you guys are having the fuel gauge problem. A bunch of the IS300 guys have this problem as well when upgrading to a high flow pump and return fuel system. My needle sometimes drops in 1/4 tank increments and I ran out of gas a few times on the road because my last 1/4 mark is my "new" empty mark now. My tempoary fix is to keep a 2 gallon tank of gas in my trunk now lol .

 

I saw the fix for this in my never ending search through the forums for stuff. When I get a chance I will try to find it for you.

First thing you should check though is make sure the pick up isn't bent.

 

holy cow! my car does the same thing. 1/4 tank=empty. but for me, when i fill up from "empty" it only takes 13 gallons

 

Jeff,
Inspect the floater swing arm. I've seen many of them doesn't come all the way down due to the walbro filter. It's a good idea to fill up the tank when your gauge is 1/4 low. Off topic, but if you have a chance to dyno the car? Make sure to post some numbers.
JPI

 

Jason the arm does have 100% movement with nothing blocking it. I usually fill my tank when it gets to around 1/4, but I just want a fully working gauge just in case of those times when I really need that last quarter. I rerouted a bunch of the pickups and lines in the tank and I think I might of fixed it. I have 2 gallons of gas in my trunk right now as a "just in case measure". I'm gonna try to run the car till it's empty so I can get a good baseline where my gas tank is empty in reference to the gauge needle.

 

Mine also is empty at 1/4 tank. It will start running lean and then I know to fill up but only takes like 12 gallons. Where is the other 5 gallons. I got a new float so I know that's not the problem. And I'm pretty sure it's not hitting the filter. Maybe it's storing fuel on the passenger side??

 

so how do we get the fuel from the passenger side over? did u change anything else out when u put ur motor in?

 

I'm starting to think that the whole system : -10 feed, -6 return and two pumps pumping under that pressure has something to do with it. The fuel on the passenger side has to circulate because the old feed was on the drivers side. I'm actually looking into getting a fuel cell. That would eliminate a lot of problems. Right now I am concentrating on the f-con getting tuned. Should be a couple weeks. Can't wait...

 

I have the same issue, just fill up at quarter tank.

 

Any update on this? My car does the same thing.

 

haha dam 4 years later

 

Only solution Ive come across talking to another member was, he actually changed his cluster for an Aristo or a TRD one; cant really remember which one at the moment, but he did mention it fixed that problem .... I too have been chasing my tail for months on this

 

Does the Aristo cluster read in kilometers? If so I don't think I would want that option. Does your ABS work ok? Did you have to install a Aristo ABS computer? I've had ABS issues since I bought my car, I don't want to spend time trying to diagnose it if it turns out the JSPEC ABS ECU is required.

 

Bippu147 is that member.

Yes, the TRD cluster reads KM's.
ABS worked just fine when I did my swap and I didn't have to use the Aristo ABS computer.

 

Thank you for the info.