My car has done more than 300,000 kms, she starts perfectly first thing in the morning.
After I leave it running for a while, it most of the times (throughout the day) takes about 5 seconds to crank before actually starting. Once started it runs fine.
Note: this happens intermittently throughout the day. But if I leave it off for say 8-9 hours, it starts fine again.
So far I have checked and cleaned:
Battery (good condition)
Mass airflow sensor (cleaned)
Throttle body (cleaned)
Use high quality fuel from BP (98 octane)
Used best quality fuel system cleaner 3-4 times when tank was empty (to diagnose the problem)
Change spark plugs (installed OEM brand)
Recently changed oil/oil filter (to make sure I'm using correct viscosity oil)
The problem is still there.
The reason why I'm not leaning towards fuel pump / filter is because first thing in the morning it starts perfectly.
One last thing, if I stop the car and start right up within 3-4 minutes, it starts right up without any issues.
Any sensible ideas from experienced mechanics are welcome
Update: Toyota Kluger 2008 V6