primo

Hello. I always put gas in my 2000 at or a little under a quarter tank. But the needle does not move right away. Eventually the gas light will come on. After a steady speed or fast driving the needle moves up to the amount I put in the tank as if a second tank is activated. Is this normal, does it have two tanks, or is it a problem?

99rx

iTrader: (6)

Seriously? Two tanks in a passenger SUV? NO. You are probably having an issue with your fuel level sending unit not reading correctly.

primo

if they can make it on a car why not an suv!?

maxSteel

If you are saying that after filling the car the fuel gauge does not show full until you drive for a while I would say there is a problem somewhere.

Only one fuel tank in the rx300.

salimshah

I will check, but the fuel gauge typically does not report the change instantaneously. As long as it responds faster that the rate of consumption, you will see good reading,

Salim

hypervish

You will also notice that at the beginning of the tank the needle will move slowly, but towards the end of the tank, the needle will start dropping faster (with the same consumption level though).

primo

Yea it's weird. Example if my tank is low. I can fill up, and the needle will not move, I can stop and go for a few short trips, then the gas light will appear as if it is empty. Then once I get on the highway. The needle will shoot up to where it is supposed to be. then it drains down normally nothing that I am concerned about just find it to be a little odd, wouldn't you say?

Lexmex

I had some issues in Mexico with my tank, and I'd just disconnect the battery and reconnect it. Took care of most issues, but sometimes there's a lot of muck at the bottom. I would use a good fuel system cleaner like Redline, Techron, etc.

salimshah

There are multiple discussions going on in the same thread here.

Normal for RX:
When the low light comes on and one fills the tank and by the time you put the ignition key ...
The low light should be off.
How long does it take to show full .... [This, i will double check but my guess is it is less than 2 mins .]

Linearity of gauge: [sorry for generalization and it is pure observation]
American cars have a substantial non-linear display. .. When you fill the tank the gauge stays pegged on full for number of miles. Lexus in general (all models) the gauge starts to move right after a tankful)


Back to primo's issue, I think something is abnormal. A sticky sender unit could be the culprit. The odd thing is that it only happens from low to high and not high to low level. Could be electrical gremlin which a power cycle would clear. Defiantly worth a shot.

Salim

maxSteel

My gauge goes to full immediately after fill up.

The gauge is non-linear though. It moves slowly from full to just below half, then quicker.
I don't know if it is symmetric as I always fill completely.

How does it behave when you fill up before you are so low?

primo

Power cycle salim, what is this? Does any one recommend Lucas fuel treatment? Max, when it is full it is normal.

carguy07

He means disconnect the battery for a few minutes and then hook it back up.

primo

Thanks car guy. Salim. I will be sure to do this over the weekend. Is this equivalent to taking the ecu, (I believe that's the right one), fuse out?