My '08 RX 350 is not starting properly. The battery is new and the engine turns over just fine. But I'm having to hold the key longer than normal to get it to start. And when the engine actually starts, it's running at an extremely low idle and then comes up to the normal idle very quickly. Then the car runs fine with no issues. Sometimes it doesn't start the first time and you have to crank it a second time. All that being said the car starts just fine at times also. Anyone have any idea why the extended crank time and low idle when it first starts?

Thanks in advance!

 

Two things to have done and most auto supply stores will do this for free.
1. Have the battery checked out under load. I have had two NEW batteries fail.
2. Have a scan tool connected to determine if any trouble codes are stored.

 

Have to agree with Rainbird.

The description of the problems in the OP were exactly what was happening when the battery started to go bad on my RX. When replaced, all of the symptoms went away.

A bad (new) battery is always a possibility. Also, make sure it has the required CCA rating for your vehicle.

 

Clean your throttle body. Check codes.

 

Check the other stuff mentioned but this also sounds like fuel pump/check valve issue

 

Had the same thing on my old 08 RX, changed the battery and all was fine again.

 

Thanks for all the input. I will have the battery checked out first as that's an easy fix. It's a 3 - 4 year old Die Hard Platinum AGM dry battery. Suppose to last 7 years. Believe it has a 4 year warranty. If that's good I will move onto cleaning the throttle body and checking for codes. I like doing repairs to my "things" like the ifixit.org website touts, the last thing I want to do is have the dealer tell me it was something simple and then hand me a $200 bill. I will post back how it goes and again thanks for the feedback!