High rpm while idle

[junklar]

Hi guys,

I've been using this forum for a while and I have solved a lot of my problems thanks to the members of this forum.

I have a 95 c280 which has around 109K miles. The car kept giving me low idle on a cold start, around 700-800 rpm in park, and I had to warm up the car for 3 minutes. Also, when I used to turn the steering wheel all the way to the right or left the car used to stall.

I decided to clean the electronic throttle actuator valve with an electrical cleaner since the spray evaporates quickly. There was a lot of oil on the butterfly lid, which lead me to the conclusion that this was obstructing the butterfly lid from opening and closing freely. Some flames did shoot up the actuator due to some spray leaking inside when I first tried to start the car, but after that it was fine. It scared the shit out of me.

After cleaning the electronic throttle actuator valve now my rpm will shoot up to 1500 rpm while in park or neutral. I no longer have to warm up the car for 3 minutes, and the car no longer stalls when the steering wheel is turned all the way to the left or right. Also, my idle is around 900 rpm and I wanted to know if there is any way to lower the rpm level. Has anyone experience this?

One more thing, with the maf sensor disconnected I still get 1500 rpm in park or neutral. Do I need to clean the maf sensor or is it the actuator?

[OzC36]

Do you think it is possible that some gunk got stuck when you were cleaning the butterfly valve and now the valve no longer closes completely at idle?

[junklar]

I cleaned the maf sensor, but that did not help. So, I bought a can of gumoff throttle cleaner for 5 bucks and I used about half the can and cleaned the butterfly valve again, and it seems that my car is good now. My rpm level while parked is 1300 and when in drive is around 800 rpm.

Before using the cleaner, the car used to shift into 2nd gear with a knocking sound when I let my foot off the brake in a couple of seconds. Now the car stays in 1st gear :)

[strictlyspeakin]

1300 in park still sounds high, but at least other problems are clearing up.

Maybe someone with a 280 will comment on their idle rpm.

Keep it up.

[OzC36]

My C36 idles at about 1000 RPM during the 12 sec cycle after start-up, and then idles at 550 RPM.

[IRISH_MERC]

My 1998 C180 Idles @ 1000RPM on start when its cold and than drops to 500RPM after about 3 mins. I assume this is normal?

[junklar]

Mine still idles at 1000 rpm on a cold start, and then it would go up to 1300 rpm. I guess it's not too bad, would like to use the car a couple more months before I get an elec. throttle actuator.

[OzC36]

I'm thinking MAF. Disconnect the electrical connector on the MAF and see what happens to the idle.

[jnolte]

on my c43 you can raise and lower idle by tightening or loosening the throttle cable, i dunno if its the same on urs