djmb

My 2000ES starts normally in regular weather or when parked in doors but stalls during starting when sitting outside in the hot sun. Ultimately it will start after a few attempts but it has touble catching.

The battery is new.

Does anyone have any answers for me?

steviej

iTrader: (1)

I wonder if it is related to fuel pump or fuel pressure at start up. Easily measured if you have the right tool.

steviej

mek88

I also have the similar problem with my 1999 RX300 @105k Miles.
When parked under the sun during summer, I have to step on the gas pedal for 10-20 sec when starting the car. Otherwise the engine dies. I plug the scanner, and there is northing wrong. I also checked the relay, fuses, spark plugs, air filter and fuel pressure. Everything seems normal.

Please help me!

Thanks
mek88@yahoo.com
Los Angeles

flipside909

Sounds like you're experiencing vapor lock.

mek88

May I know how to fix this vapor lock?
Is there anything need to be replaced?
Thanks
Mek88@yahoo.com

lexusk8

mek88, you might want to take a look at your throttle body. It could very well be that inside the body is filled with carbon, grime and fuel vapor, and so needs to be cleaned out. A bottle of specialized carb/choke/throttle body cleaner is sufficient for that task, and you can get it at your local auto parts store or Wal-mart. Also, while you're at it, check the air filter and its condition. If it's quite dirty, replace it. Let us know if you have any problems.

mmarshall

What kind of gas are you using? Some brands, octanes, and mixtures are more susceptible to vapor lock than others. Try a different brand and see it that helps. Chevron and Mobil have good detergent additives. Amoco ( now with BP) traditionally has done an overall high-quality fuel.
Also have the Coolant-temperature, mass air-flow, throttle-position, and oxygen-sensor checked. Even though you didn't get a scanner code, sometimes these items can malfunction and not show up on the scanner.

mek88

I always use Chevron, and I just put a bottle of Techron fuel cleaner less than 1000 miles ago.

Now, I notice more problem:
After driving for a while, I stopped @ a store for 10-15 minutes, then the engine fail to start. I have to press the gas pedal for 10-20 seconds to keep the egine running.

So now, not only it is hard to start when engine is cold & the car parked under the sun, but also when the engine is hot.
And it seems these problem occur more often than ever before.

In the morning & at night, the 99-RX300-AWD starts fine.
Do you think the main relay or Fuel pump relay need to be replaced?
I've run a search on the internet and found the similar problem to Honda Accord at: http://autorepair.about.com/cs/troub.../aa010301a.htm

May I know, where is the location of the main relay?
I found an EFI relay on the engine compartment, but I couldn't fine the main relay.

Thanks
mek88@yahoo.com
Los Angeles

steviej

iTrader: (1)

have a shop measure the fuel pressure upon cold startup and when hot.
mmarshall's got some ideas, too. I especially like the coolant temp. sensor. It is true that even though a trouble code is not sent, the sensors can be lazy and send misinformation to the ECU thus changing the fuel/air settings.......and badda bing badda boom.....stall or no start.

steviej

gmac1337

This problem happened on our 2001 rx300. The engine would struggle to start but it wouldnt work in hot weather. Had lexus attempt to repair it three times but nothing worked. Ultimately the problem stopped but it sure was frustrating when a brand new lexus does not start. Best of luck with your problems.

flipside909

This definitely sounds like some sort of electrical sensor problem. Have you looked at your MAF sensor lately? When the little probes get dirty, they tend to trip out the ecu give you that no-start symptom. Have you gotten a diagnostic check lately?

Edit: Coolant temp sensor usually just affects your engine fans and erroneous guage readings.

mek88

I found a similar situation with me, not sure if this is the correct solution on my Rx300:

https://www.clublexus.com/forums/sho...arting+problem