ML 320 Hard Starting

[df666]

Hello Everyone,

I have a 2000 ML 320, and for months now it will not start on the first attempt. The starter just "times out". However, on the second attempt it will start right up with no problems. Once the engine starts there are no problems. If I turn off the vehicle (after running) and I start it up, it will start up right away. The hard starting will occur if the vehicle sits for 20mins. or longer. There are no codes.
The fuel filter has been replaced (the hard starts were occuring before replacement) and the fuel injectors have been cleaned, flow tested and blueprinted (I highly recommend this service), the fuel pump relay was replaced and the CPS was also replaced. I doubt the fuel pump is bad, I would think if the fuel pump were defective, the vehicle would not start or run at all.
Has anyone experienced anything like this? And if so, does anyone have any recommendations as to what I should look at next before going to the STEALER or mechanic?
Thanks in advance for your help, Happy Holidays everyone!