99 s320 w140 idle bounce 200 rpm
 

Yes my car at certain temps has a idle bounce,also effects crusing at 0 t0 55
Did you think throttle body wires,or something to due with ildle,thinking of cleaning the butterfly valve in resonance valve

after looking everywhere I'll try a new Maf sensor,if that don't fix it,I will rewire throttle body

Have you tried cleaning both the MAF & the throttle actuator?

I keep Maf clean but it might be old,no rough idle though. I'd like to clean actuator just don't know where it is

still don't know where actuator is guys

The actuator is bolted to the intake manifold.

thanks doc

On the 104 it is under the intake, not an easy thing to see. If it loses synchronizationusually they will resynch just by letting them sit a minute or so with the key on. But if it does lose synch it it a really pronounced up and down idle, sort of can imitate it, sound like "rumrumrumrumrum"

Can it be cleaned up? also will check my nozzle added to crossover for the nitrous.
Boy runs like a she devil when activated Killed a 90 model Mustang GT,325i's, S500,Caddies,Linclons,most new cars,hyundas,accord v6's.

Yes but I would venture to say it needs to be removed to clean it.

would carb cleaner be ok?

would carb cleaner be ok?

Ah, sure, that would actually be the ideal stuff to use.