My 2004 C240 4Matic has major problems accelerating from a stop. It does pick up relatively well (considering the anemic engine on it) when the weather is cold, but when is hot outside it is a matter of luck and patience to get it going (the hotter outside the slower the car). Once it goes above 30 miles the acceleration works a little better meaning that it only has a one second lag between the time you press the pedal and when it actually accelerates. I have no CEL on or any codes MAF and tranny fluid are new (same behavior trigger replacing the two).
Yes, I know it is a toy engine, but when I say slow acceleration it means the car starts as slow as one person would push it up to 10 mph then regardless if you press the gas 1/2 or floor it.

Any idea what could cause this odd behavior?

Thank you in advance for all your feedback!

P.S. Idling is a bit erratic but not too much more like when the gas is not a quality one I'll check today for vacuum leaks if in addition to any other ideas on where to look for the issue, you guys have any idea which vacuum hoses to focus on this engine that would be great