Fluctuating rpm at idle

[Nissan101]

So today i changed my MAF
At idle my rpm keep fluctuating (about +-50 rpm)
The car has been properly tuned up (spark plugs, throttle body, air filter etc)
What can be a cause of this and do note that before my MAF change it had this same problem (i thought the MAF was contributing to this problem)
thanks

 

[mclasser]

Air in the cooling system, bad IACV, vacuum leak.

 

[Nissan101]

Im more thinking in the direction of the IACV
Can it be serviced or the entire unit needs to be replaced?

 

[Rolla07]

Check for vacuum leak first

 

[RationalRussian]

Typically when you install a part like that it requires you to drive the car for it to get used to the sensor. It's definitely the case with an IAC sensor

 

[KingCake]

Oh boy another parts swapper. Fire the parts canon! Maybe this will teach you to have proper diagnostics performed. You likely replaced your MAF with an inferior product while simultaneously lightening your wallet.

Clear the KAM and relearn. +/- 50 is not a big deal you shouldn't even be able to see that on tach.

 

[Merkava_4]

Carbon buildup between the throttle body and the butterfly will cause surging at idle.

Same thing with carbon buildup in the IAC passageway.

Solution ? Take throttle body off the engine and remove all carbon from everywhere.

How you do that ? Throttle body cleaner, Scotch-Brite pad (the white one), acid brush, toothbrush.

 

[Nissan101]

-_-
My MAF needed to be replace as it was bad from a diagnostics
and my MAF is an oem replacement

 

[Nissan101]

Yeah thanks thats my next action to be done

 

[tomcat27]

Like merkava said, clean the IAC and the intake/throttle plate