High idle - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old 12-11-2018, 10:58 AM Thread Starter
BenzWorld Extremist
 
gogi's Avatar
 
Date registered: Jan 2008
Vehicle: 1991 560sec. 1969 280SL
Location: New Jersey
Posts: 856
Mentioned: 6 Post(s)
Quoted: 232 Post(s)
(Thread Starter)
High idle

I have no vacuum leaks, tried another idle control module and a idle control slide valve. The high idle is intermittent and is 1000rpm when it gets normal itís 550-650. Iíve unplugged the TPS and the idle shoots up so, thatís functional.
Thoughts please. Thanks.
gogi is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old 12-11-2018, 01:02 PM
Moderator
 
ianrandom's Avatar
 
Date registered: Jul 2008
Vehicle: 1986/1990 W126
Location: Berkshire & Devon, UK
Posts: 12,873
Mentioned: 28 Post(s)
Quoted: 1161 Post(s)
Lifetime Premium Member
I will say try some more valves and idle units if you can. I had three faulty valves but didn't imagine all 3 could be faulty. Took me ages to figure out that's all it was.

'86 420SE
'90 420SEC


Daily transport 9spd Giant DH Comp downhill bike
ianrandom is online now  
post #3 of 13 (permalink) Old 12-11-2018, 04:12 PM
Outstanding Contributor
 
luckymike's Avatar
 
Date registered: Mar 2010
Vehicle: 1989 560SEC, 1989 560SEL, 1995 E420
Location: NorCal
Posts: 3,788
Mentioned: 7 Post(s)
Quoted: 553 Post(s)
Look closely at the wiring at the idle control valve. I believe it was 281lxm who had broken wiring that was causing a problem.
281lxm likes this.
luckymike is offline  
Sponsored Links
Advertisement
 
post #4 of 13 (permalink) Old 12-11-2018, 04:24 PM
Lifetime Premium Member
 
281lxm's Avatar
 
Date registered: Dec 2011
Vehicle: 1991 560 SEC 1994 E500 2014 E350 Cab
Location: Houston, TX
Posts: 7,014
Mentioned: 3 Post(s)
Quoted: 435 Post(s)
Lifetime Premium Member
Garage
I agree, pull electrical plug from the valve. If idle stays High, you have broken wires or a stuck valve. I recently gave Euro500 a length of wire with a cap for the same harness - this case it was the temp sensor. If you are board, rebuilding that harness for temp, idle 6Ē up with heavier gauge wire a d hear rated shrink is a good mod.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

_____________________________________________
1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood refinish and restored.
281lxm is offline  
post #5 of 13 (permalink) Old 12-11-2018, 04:34 PM Thread Starter
BenzWorld Extremist
 
gogi's Avatar
 
Date registered: Jan 2008
Vehicle: 1991 560sec. 1969 280SL
Location: New Jersey
Posts: 856
Mentioned: 6 Post(s)
Quoted: 232 Post(s)
(Thread Starter)
Quote:
Originally Posted by 281lxm View Post
I agree, pull electrical plug from the valve. If idle stays High, you have broken wires or a stuck valve. I recently gave Euro500 a length of wire with a cap for the same harness - this case it was the temp sensor. If you are board, rebuilding that harness for temp, idle 6Ē up with heavier gauge wire a d hear rated shrink is a good mod.
I wish it were that simple. There is no break in the wiring my high idle is no more than 950 to 1k rpm. If I unplug the ICV the idle shoots up past 1500rpm. If I unplug the ICM it shoots up the same. The idle is intermittently going up.
gogi is offline  
post #6 of 13 (permalink) Old 12-11-2018, 04:42 PM
Lifetime Premium Member
 
281lxm's Avatar
 
Date registered: Dec 2011
Vehicle: 1991 560 SEC 1994 E500 2014 E350 Cab
Location: Houston, TX
Posts: 7,014
Mentioned: 3 Post(s)
Quoted: 435 Post(s)
Lifetime Premium Member
Garage
Are you calling the Idle Control Relay The ICM?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

_____________________________________________
1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood refinish and restored.
281lxm is offline  
post #7 of 13 (permalink) Old 12-11-2018, 04:47 PM
Lifetime Premium Member
 
281lxm's Avatar
 
Date registered: Dec 2011
Vehicle: 1991 560 SEC 1994 E500 2014 E350 Cab
Location: Houston, TX
Posts: 7,014
Mentioned: 3 Post(s)
Quoted: 435 Post(s)
Lifetime Premium Member
Garage
I donít have all the values here at the dinner table but voltage checks at each connection and possibly at X11 DS fender.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

_____________________________________________
1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood refinish and restored.
281lxm is offline  
post #8 of 13 (permalink) Old 12-11-2018, 05:47 PM Thread Starter
BenzWorld Extremist
 
gogi's Avatar
 
Date registered: Jan 2008
Vehicle: 1991 560sec. 1969 280SL
Location: New Jersey
Posts: 856
Mentioned: 6 Post(s)
Quoted: 232 Post(s)
(Thread Starter)
Quote:
Originally Posted by 281lxm View Post
Are you calling the Idle Control Relay The ICM?
Yes, idle contro module or relay.
281lxm likes this.
gogi is offline  
post #9 of 13 (permalink) Old 12-11-2018, 06:53 PM
Lifetime Premium Member
 
281lxm's Avatar
 
Date registered: Dec 2011
Vehicle: 1991 560 SEC 1994 E500 2014 E350 Cab
Location: Houston, TX
Posts: 7,014
Mentioned: 3 Post(s)
Quoted: 435 Post(s)
Lifetime Premium Member
Garage
Check your ovp relay, perhaps change the fuses. Or just replace with MB version. These things donít respond well to battery tender, so precaution would be to unplug the relay while it trickles.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

_____________________________________________
1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood refinish and restored.
281lxm is offline  
post #10 of 13 (permalink) Old 12-13-2018, 06:32 PM
RNT
BenzWorld Senior Member
 
RNT's Avatar
 
Date registered: Jul 2007
Vehicle: 1985 Mercedes 380SE Metallic Navy Blue
Location: South Carolina
Posts: 407
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
I have had high idle prob for a while. At start I have high idle 1200 and it stays there. Some days but not always, it starts at 5-600 and after a while it jumps quickly to 12-1300.
My question is: Aside from the Idle Control Valve, is there anything else that could cause the problem? I have replaced all fuses.
RNT is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W126 S,SE,SEC,SEL,SD,SDL Class

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome