Hello All,

I believe I have found a solution to your all engine stalled, at least it worked for me. Three solutions to this symtom, but it depends on your situation when your engine is warmed up or cold.

-If your engine is cold at start up in the morning and the engine shuts right off, then it is the Cold Starter Valve or the Air Intake Valve needs to be cleaned. The Air Intake Valve is easy to clean with Gumout spray. The Cold Starter Valve was cleaned by the dealer and that was what they said it was the problem after they fixed it, and it sounds reasonable to me.

-If your engine is at a normal temparature and it stalls when idling, at red lights, etc, turning your A/C on will increase the idle speed helping it not to stall. Cleaning the Air Intake Valve does help, even if it does not resolve your problem, it helps to smooth up your gas pedal and the valve itself so you will not waste your time there. But I have found the actual cause on this symtom when my brothers car 2001 ES300, ( I am RX myself and this problem will occurs on any vehicle with this sensor) stalled at a normal temperature. This is a big job to resolve!! It is the engine speed sensor that causes this problem. Once the sensor is dirty, for some reason it will send a signal to the ECU or something to shut down the engine. Over time the sensor is cover with a layer of oil burned like, that is very hard to remove; like a cooking pan fried oil. if you have a better way to clean it please keep us posted. We had to sand it down nicely with fine sand paper. the sensor looks like an aliminum Capacitor. This problem occurs on any car that has this sensor not only lexus. The sensor is located right at the engine pulley, the job to clean this sensor is the same as replacing timing belt. You have to remove the timing belt cover to access to it. After we cleaned it, the engine starts right up with no trouble. This problem will recur when this sensor is dirty again. Cleaning the Air Intake Valve is a good idea every 15k when the car has 30k on it. If you pay attention on your gas pedal, you will feel the stickiness of the pedal movement, it is time to clean the Air intake valve.

Good luck to All