jrobertg

Our RX300 is hard to start and then stalls whenever we let the fuel level get low (1/4 tank). This happens when the car sits for a while, overnight or a day at the office.

I thought it might be the fuel filter. Some posts have indicated the fuel filter is a lifetime part and stalling problems may be from a faulty check valve in the pump.

lexus114

it could also be your iac valve.although that doesnt explain the below a 1/4 of a tank thing.

salimshah

Next time engage the key and switch it to "on" or "run" ... detent before start. Leave it there for about 30sec to a minute and then try to start. In this position the fuel pump is supposed to prime-up and have the fuel available at the injectors.

Also tell us, once started.. how does it keep up with fuel demand when you drive?

lexus114

you might want to try some BG fuel injector cleaner very,very good stuff.You can get it on e-bay.

jrobertg

Salimshah, Once I get it to idle it works fine. The key is to get it past the stalling period, about 30 seconds of manual reving.

lexus114

that sounds to me like your iac valve.

salimshah

Then it seems like a 'cold idle' problem and the fuel level in tank is a coincidence.

If you still think it is a fuel pump/delivery issue ... have a mechanic perform [do it with 1/4 tank condition that you mention]
a) Fuel pressure test. [this is NO flow just pressure]
b) Fuel flow test [this checks the volume/time]

Others can suggest test/remedy for 'cold idle'. These days it is all controlled by ecu and which gets input form sensors and the ecu sends the appropriate signal to the certain valves. lexus114 suggested the IACV.

Salim