1991 190E 2.6 high/rough idle - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 03-15-2011, 06:23 PM
BenzWorld Junior Member
 
Date registered: Mar 2011
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
1991 190E 2.6 high/rough idle

1991 190E 2.6 5speed high rough idle. Hot or Cold it idles around 1200-1400 rpms and the car shakes like it's running on 5 cylinders. When I give it gas it smooths out.

When I'm driving it's ok, but I can push in the clutch and the rpms drops to 1200-1400( it won't go lower) it shakes again. I check the fuze on the OVP and that looked OK. I removed the ICV and soaked it in WD40 overnight.

I just put it back in and no change, still 1200-1400 and rough idle. I then pulled the connector off the ICV and the idle dropped to 700-800 rpms where it should be but still shook. Any ideas? I thought I saw a comment about a 3 wire coolant sensor? Thanks for your help
Kenmsby is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 03-15-2011, 07:20 PM
IR MODERATOR
 
Jippi's Avatar
 
Date registered: Aug 2002
Vehicle: 1996 Volvo 855GLT, 1993 MB 190e 2.3 8v, 1998 Subaru Outback SUS, 1991 BMW 525, 1998 MB C230
Location: somewhere in NJ or PA
Posts: 9,207
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Lifetime Premium Member
Send a message via AIM to Jippi Send a message via MSN to Jippi
MAINTENANCE HISTORY


1993 MB 190E 2.3 105k- its alive.. 1996 Volvo 855 GLT-R 350k still rolling
1998 Subaru Outback SUS 210k- Daily Driver 2011 Toyota Camry XLE 36k
1991 BMW 525I stock as stock gets 98k (Wrecked) 1998 MB C230 209k possessed by the devil
Benzworld.org---Tri-State Crew
Jippi is offline  
#3 (permalink) Old 03-16-2011, 04:39 PM
BenzWorld Member
 
johndevone's Avatar
 
Date registered: Jul 2010
Vehicle: 1984 190 E
Location: Los Angeles, Ca.
Posts: 72
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Is your micro-switch on the throttle lever engaged when you are at idle. It should just touch when the pedal is released. It will drop the RPM down.
johndevone is offline  
#4 (permalink) Old 03-16-2011, 05:04 PM
BenzWorld Junior Member
 
Date registered: Mar 2011
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Thanks, I'll take a look at that micro switch.
Kenmsby is offline  
#5 (permalink) Old 03-17-2011, 09:50 AM
BenzWorld Member
 
johndevone's Avatar
 
Date registered: Jul 2010
Vehicle: 1984 190 E
Location: Los Angeles, Ca.
Posts: 72
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Look at this pic from a member. http://www.benzworld.org/forums/w201...e-control.html
The micro switch is the grey box. You will find this next to the carb.
johndevone is offline  
#6 (permalink) Old 03-17-2011, 03:03 PM
BenzWorld Junior Member
 
Date registered: Mar 2011
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Ok, I found the micro switch and it is resting against the throttle. If I move the throttle the micro switch does come out some more. I pushed on the roller and I did hear a clicking noise.
Kenmsby is offline  
#7 (permalink) Old 03-17-2011, 03:19 PM
BenzWorld Junior Member
 
Date registered: Mar 2011
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
I found part of the problem. When playing around with the micro switch while at idle I noticed that the last intake port ( closest to the fire wall) had what looked like a vacuum port with no tubing on it. I put my finger on it and the rough idle started to smooth out. So I guess that piece of tubing that would have sent some place else fell off. I looked around but didn't see it. Any idea where that should go, to or from? Thanks...
Kenmsby is offline  
#8 (permalink) Old 03-17-2011, 03:25 PM
BenzWorld Elite
 
Nfsjunkie91's Avatar
 
Date registered: Aug 2010
Vehicle: '87 190E 2.3 Running MegaSquirt 2 Extra
Location: Western Maryland, USA
Posts: 1,733
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by Kenmsby View Post
I found part of the problem. When playing around with the micro switch while at idle I noticed that the last intake port ( closest to the fire wall) had what looked like a vacuum port with no tubing on it. I put my finger on it and the rough idle started to smooth out. So I guess that piece of tubing that would have sent some place else fell off. I looked around but didn't see it. Any idea where that should go, to or from? Thanks...
Check the FAQ for vacuum routing diagrams. If you live in the US, you can use the EPC-net to look it up.
Nfsjunkie91 is online now  
#9 (permalink) Old 03-18-2011, 04:46 PM
BenzWorld Junior Member
 
Date registered: Mar 2011
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
OK, I found the problem. That metal tube that sticks out of the intake manifold on the #6 cylinder closet to the firewall needs to be plugged. I actually found the short tubing (blocked on one end) lying on the side of the transmission and just under the firewall. You won't find that on any vacuum diagram. It must have vibrated off. So I put it back on, started the car and the idle was a little high which is normally for a cold engine, but it didn't shake any more. After it warmed up( you also have to tap the gas pedal, linkage must need to be lubed)the RPMs dropped to 700-800. I drove it around the block and it was fine.

Now on to the next challange. I'm going to replace the distributor cap and rotor. Doesn't look like must room with the fan and the radiator in the way?
Kenmsby is offline  
#10 (permalink) Old 03-19-2011, 07:15 AM
BenzWorld Member
 
Date registered: Jan 2005
Posts: 91
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There's a couple of ways to take the dist. cap off. One way is to remove the fan cowling and fan...not too long with the right tools. The other is to make a special tool out of the right 1/4" drive allen key, a short extension, and a box end ratchet drive. Then you find the larger spacing between the fan blades and use this tool to loosen the allen screws. The top two are no big deal. but the one underneath is a tad exasperating. The cowl and fan removal is probably the easiest way.
MDE3 is offline  
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W201 190 Class


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Topic Author Forum Replies Last Post
1991 500sl Running Rough on Idle scorpiox R129 SL Class 8 12-30-2013 07:53 PM
1991 300E Rough Idle and CE light on jethroebodeen W124 E,CE,D,TD Class 0 08-18-2010 03:01 PM
1991 500E Rough Idle hunter500 General Mercedes-Benz 4 08-15-2010 12:43 PM
High neutral idle + once in gear way rough idle Rickysa R/C107 SL/SLC Class 3 04-12-2008 12:50 PM
Rough idle Vs high idle NewMBie W126 S,SE,SEC,SEL,SD,SDL Class 3 12-29-2004 09:17 PM

Posting Rules  
You may not post new threads
You may not 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

 
For the best viewing experience please update your browser to Google Chrome