420sel idle help
 

I've searched a lot of threads on this subject. My 420SEL has a 1000-1400 RPM idle all the time. I cleaned the ICV and it resolved the idle issue for about three start-ups and then it went back to normal at 1k. I then disconnected the cruise control thing at the front of the engine and then the idle went to normal for about three start-ups and then back to 1k again. I can feel the ICV vibrating when the ignition is on so I assume it works. I looked over all the linkages and everything looks to be normal. Is there anything non-electronic to look for besides vacuum leaks that could cause high idle?

Check your Idle Control Unit.

http://i179.photobucket.com/albums/w...6420SELICU.jpg

I pulled the idle control unit out and looked at it. I made the idle go up. The same thing happens when I pull the connection at the idle control valve. I measured the voltage at the connector for the ICV and only got like a varying 2-3 volts. I can feel the ICV vibrating when charged, but I have never been able to hear it click like some say it will. Is there a sure fire way to test The ICU? I have spent 600 dollars on this car in the last 2 months and cannot afford 500 more in a new ICU and ICV with Christmas coming up and what not.

it's been my experience that a constant idle of approx 1000 requires a new idle valve to cure it.

I know its been a long time since I posted this, but I finally got a new ICV and it cured my high idle. However, it idles at 500 or so in park. Is that normal?

I am running at 1500 and i was told that it was normal.

No, most of the m116 and m117 engines run about 500/700 in drive/neutral.

-Troy

that cant be right. mine was idling at 1000 in park and it caused it to slam into gear. right now its at 600 in park and 500or so in drive.

and that is correct.