well, it's been 3 weeks now. the car starts fine on normal days. it just won't start on random days... But when I turn the key with the foot pushing the gas pedal, then the car starts. what could be the problem? any ideas?!?

 

This coud be a possible solution --

https://www.clublexus.com/forums/rx-...-write-up.html

No codes (Check Engine light) I pressume?

 

2 suggestions 1 mass air flow sensor. 2 more likely idle control valve, this seems to get dirty over time& can be cleaned as oposed to replacing, search idle control valve on this site.I can't remember where I found it.

 

Run some fuel injector cleaner through it. I've had the same issue on occasion a few times in the last year. Only other issues I remember bringing this about were I hadn't started the vehicle in a week and I have a 5 year old Optima battery. In addition, with some gasolines that I've tested (other than my favorites), when I get under 1/4 tank, I sometimes have issues starting.

 

yeah I don't have the check engine light on. I think I will try to clean out the idle air control valve. Thank you!!

 

actually, I poured in shell engine cleaner last week. But i guess that did not help?? Also, my battery is one and a half years old so I hope it's not a battery problem BTW do you use premium gas on your car? I've been using premium, but I recently put plus in it. maybe that's the problem??

 

As long as your battery can spin the engine at a reasonable rate, you can eliminate it.

Your RX can take plus, so that is not the problem too.

Since you need more gas (via pressed pedal) the problem is with amount of gas and air at idle .. which is the function of IACV. Follow the thread and instructions and most likely the problem will be solved.

Be very careful with the phillips head screws. Use a good screwdriver and tap the back of the screwdriver with soft hammer blows to seat the screwdriver and the jar the screw.

Salim

 

99% of the time I use Premium because of my modifications to intake/exhaust (hates anything less than about 92/93 octane).

Keep in mind that even though you just put in the fuel injector cleaner, there can be muck at the bottom of the tank that gets stirred up. I've gone through the same thing in Mexico and here in Florida (when I was still cleaning all the gunk brought back from Mexico). Thus, it takes a bit of time to work.

Cleaning the IACV will help.