Greetings..

My old trusty 1986 420-SEL just started idling at about 2500 RPM. I have checked all the linkage for proper operation. Also checked for vacuum leaks. I am suspecting the idle air control device may be gummed up, or just plain bad. But there are no warning light present in the cluster. Any suggestions other than replacing it??

 

you get no warnning light or others, idle contol relay is on firwall is bad it is on the center of the fire wall with two 10 mm nuts attached, if you send me the part number i may have a good used one,

 

Thanks.. I will check into it tomorrow..

 

If the idle control relay is not the culprit, it could be your Idle Control Valve. I think I do have a very good clean one.
nes

 

check the overload protection relay, there is a 10 amp fuse on top of it, if it is blownthen it will causeyour engineto idle high, it is located next to the fuel pump and klima control relays just to the left side of the brake booster, it has a red top with a clear lid that pops up, check it before you go spend $$$$$$ replacing parts that are not bad, hope this helps out.

 

this is a pic of the idle speed control valve, located at the front of the aircleaner partially under it. usually when you unplug it the idle should change. if you unplug it and nothing happens it could be a bad valve.

[IMG]local://upfiles/20215/956B58CF6BEC4EE9A1F930798B66A374.jpg[/IMG]

 

did you figure it out?? i have the same problem but cannot recieve a response. i would really appreciate any advise you can give.

 

CHECK THE IDLE CONTACT SWITCH, SERIOUSLY