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 03-06-2003, 12:45 PM
Registered User
Join Date: Mar 2003
Posts: 50
Question CANNOT SET LAMBDA ON 89 300e please help

i am trying to set the lamba on my 89 300e i have and open crcuit somewhere i have to diffrent fluke meters on the car fluke 88 is set to a fixed 70 and fluke 83 is fixed 30 i sent both meters to fluke to get calibrated they are both fine fixed 30 sends me to a coolant temperture problem and fixed 70 sends me either to the td pickup or crank postioning sensor how should i tackle this both meters are set the same on percent should since both meters are reading 2 diffrent settings what next thanks for the help
Reply With Quote
Old 03-06-2003, 01:04 PM
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Duty-cycle is often called On-Off ratio but if it were called Off-On ratio it would be the inverse.

Duty-cycle point of reference can be changed on most good meters (including those flukes). If the duty-cycle on is 70% then the duty-cycle off is 30%. You have to decide which period you are talking about.

As a point of reference your car should have a 70% duty cycle with the key on engine off. Verify and correct your point of reference on this number. (If your car is a Ca car it will be 85% instead of 70%)
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
Old 03-06-2003, 01:47 PM
Registered User
Join Date: Aug 1999
Location: Florida / N.H.
Posts: 8,768

Check section on Duty Cycle....
Reply With Quote
Old 03-06-2003, 06:58 PM
pesuazo's Avatar
Registered User
Join Date: Oct 2002
Location: Near Raleigh, NC
Posts: 580
Wow, I just keep learning

Well, another lesson learned.
I was wondering why my Duty Cycle was at 30% with the ignition on engine off. After reading this post I realized my meter reads duty cycle, but the opposite way (Off/On). And no option to inverse the reading.
To make sure, I disconnected the coolant temp. sensor with the engine idling and it got locked at 70% (the manual states a fault for the device at 30%). Hmmm??!!, makes sense.
I tried another test for assurance, my meter reads a duty cycle at idle and 2500 RPM of 40-50%.
So in reality it is 50-60% (slightly lean); I measured the current at EHA and oscillates between 0 to +1.2 mA. A positive current means a compensation for a lean condition. (The opposite of -3 mA for a 38% rich condition, from stevebfl article in the DIY section).
I hope this helps someone out there.
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified
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

All times are GMT -4. The time now is 06:13 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