c240 v6,intermittant sluggish acceleration.

[stephentanks1]

My c240 accelerates very well until about half warmed up then the performance drops off.Sometimes it will pull away like a jackrabbit other times its slow.Also if the engine is hot and its left for about 15 mins and you then drive off its almost as if its starved of fuel and feels as if it is not going to accelerate away.Its not the winter/summer gearbox switch,I have tested this a lot.Its had a new "cat",MAF sensor,but not genuine Merc ,and new lambda probes.Any ideas please.

 

[BlackC55]

Where did you get the air mass from?

Only fit gen MB or a Bosch item.

 

[television]

Where did you get the air mass from?

Only fit gen MB or a Bosch item.

Get one from any bosch service center, ½ the MB price

 

[jberks]

I'd go with the above, none genuine MAFs have been known to give problems. That said, I've not heard of MAFs being temp related so I'm not convinced.
Thinking back, i had a similar issue with a Ford once. Turned out to be a knock sensor weakening the mixture until it was running on thin air. Was ok when cold as it richens the mixture so ran ok, but once warm it ran very badly. Very economical though!

Not sure if a Merc has a knock sensor or even what they are, but maybe Malcolm or BlackC55 could shed some light.