W210 tries to stop engine

[sub_zero]

Hi all,
my friend has a W210 E200 1997,his car is doing something odd these days,
while idling the engine tries to stop itself (rpm pointer hits the 0 rpm ) then it goes on without stopping!!! this is cyclic(every 3 or 4 minutes).
At first I thought the AC compressor is cutting in and out,but this also happened
when the AC is off.
While driving,this also happens but since your foot on the pedal the car just has rough driving every once in a while.
I have doubts on the air mass,but decided to ask the gurus first.
What do you think?
Hope my English was clear enough
Thanks in advance

 

[renault12ts]

MAF or Crank position sensor (CPS) would be my guess.

 

[sub_zero]

thanks

 

[shorty]

Has the car been checked with STAR dignostics , this would tell which sensor has failed , could save the owner buying parts that might not be needed

 

[sub_zero]

No we didn't STAR check it,but before we check it we can have prior knowledge
what is the problem as workshops here are not trusty.
Can I unplug the MAF and check whether the problem sorted or not?
IF sorted then the MAF is the problem,or still maybe some other suspects?
If not sorted then MAF is innocent.
Right?

 

[renault12ts]

Yes, unplug and see what happens.