Rx350 intermittent starting problem

[Rincewind35]

I have a 2007 rx350 with just over 60k on it.

Whilst it’s a great car I’ve started having intermittent starting problems whereby the car will crank over but not fire.

It’s not usually the cold start in the morning but usually during the daytime say at work after an hour or two

you can usually get it started by cranking it and flooring the throttle but it takes a while to catch 

 

[BachelorDays]

On an MB you wouldn't think twice and change the Crankshaft Position Sensor (CPS). But you don't see it mentioned as an issue with the RX. You could check the connector on it. I don't know it's exact location in the RX and I'm not near my car these days.

Flooring the throttle doesn't do anything since the starting mixture is controlled directly by the ECU.

[Delphius1]

I'm with BatchelorDays. Cam or crank position sensor is the usual suspect, but confirm by reading the codes from the engine management system.

An altwrnative bet could be not reading the immobiliser chip in the key. 

Reading codes from the OBD2 port will point you in the right direction.