Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 03-19-2001, 01:15 PM
Posts: n/a
I have a 85 190E 2.3. Want to know how I can adjust the fuel-air mixture myself - everytime I get the car back from the shop, they set it too rich - fuel mileage is low. so I have to go back and get the mixture leaned out. What specific tool do I need? Is the mixture screw the one right in the middle of the air filter housing in the hole? Also, what damage can it do to my car if I let it run rich?

Thanks very much for all your help.

Reply With Quote
Old 03-20-2001, 02:37 PM
Posts: n/a
Would anyone please reply to my post and help me out?

Reply With Quote
Old 03-20-2001, 05:01 PM
Registered User
Join Date: Feb 2001
Location: BC, Canada
Posts: 378
I'm not a tech, so take this advice for what it is worth, (not much).
Yes, the hole you are refering to is the mixture adjust point.
There may be more to adjust that I don't know about yet. To adjust,
you need a special, long allen key wrench. I don't have one so
I can't tell you how long. I think that the Merecedes CD shows the
tool with it's part number and possibly it's length.
Don't change the setting much; you don't want to make it worse.
As for running rich, as far as I know, you can't hurt much.
You likely work the catalytic converter more and have higher
1967 250SL
Reply With Quote
Old 03-20-2001, 05:41 PM
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
To adjust requires a 3mm allen wrench. Turning the adjustment clockwise richens, ccw is leaner. To know what you are doing there are two methods.

One involves monitoring the integrator on the #3 pin of the diagnostic socket on the left fender. This will require a faily good multimeter with a duty-cycle range.

The second and more informative way is to monitor EHA current with a cheap multimeter (one with a 2amp scale).

Both methods are described in the DIY article "evaluating engine controls". The value you are going for on an early 190 is 8ma with an oscillating reading (plus a ma or two and minus a ma or two). Remember that a dead (or disconnected - to verify your system try disconnecting the O2 sensor and you should get 8ma EHA current or 50% duty cycle on the integrator) O2 sensor will give a fixed reading of 8ma when warm (so it can't be adjusted by either method - both methods monitor the closed loop lambda cycle).
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
Old 03-20-2001, 06:26 PM
Posts: n/a
Thanks for your responses, Steve and Vaughn. I was reading somewhere that for moving the fuel misture screw, I should press down with the wrench - is that true?

One more issue. How harmful is it for the car if its running rich (fuel consumption up by 10-15%) - in terms of carbon build up in the engine, and clogging up of the cat. converter. My mechanic said - "Oh its fine, it won't hurt your car". But I'm not so sure. Any insights/experiences would be greatly appreciated.

Reply With Quote


Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
240D Top Speed ? Benz240D Diesel Discussion 73 07-04-2011 11:48 AM
DIY Notes may help people: Radiator, Fan Clutch, Temp Sensors, Fuel Pump, Temp Gauge ericgr SL Forum 3 09-24-2004 01:40 AM
fuel mixture adjustment denismitchell Tech Help 1 03-09-2004 08:50 AM
94 C280 starting help needed! Duke1Law Tech Help 1 06-13-2003 02:12 PM
86' 190e 2.3 8V fuel mixture adjustment kjsabat Tech Help 1 11-21-2002 03:13 AM

All times are GMT -4. The time now is 10:35 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page