Notices
928 Forum
Sponsored by:
Sponsored by: 928 Specialists

LH 2.2 MAF/CO adjustment LED (85-86 US)

 
Old 06-23-2016, 12:08 PM
  #61  
coach928
User
 
coach928's Avatar
 
Join Date: Jun 2016
Location: Redwood City, CA
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Default Blinkr sets MAF pot to 2 ohms???

i'm a new 1986 928 owner, and I built my own adjustment tool and Blinkr per the instructions. Blinkr only blinks at MAF pot setting of 2 ohms. When I temporarily adjust MAF to 380 ohms, startup from cold is wild until O2 sensor warms up.

Is MAF pot setting of 2 ohms a sign of a failing MAF or O2 sensor? Could this be related to my high NO emissions?

I started a related thread with more details:
https://rennlist.com/forums/928-foru...on-blinkr.html
coach928 is offline  
Old 06-23-2016, 02:07 PM
  #62  
John Speake
Addict
Rennlist Member
 
John Speake's Avatar
 
Join Date: Feb 2002
Location: Cambridge England
Posts: 6,891
Likes: 0
Received 0 Likes on 0 Posts
Default

A setting of 2 ohms would give a very weak mixture - if the MAF is aged it would be even weaker.

Aged MAFs would need more pot resistance.

Sounds like the measurement system is the problem.
John Speake is offline  
Old 06-23-2016, 02:33 PM
  #63  
coach928
User
 
coach928's Avatar
 
Join Date: Jun 2016
Location: Redwood City, CA
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by John Speake View Post
A setting of 2 ohms would give a very weak mixture - if the MAF is aged it would be even weaker.

Aged MAFs would need more pot resistance.

Sounds like the measurement system is the problem.
The measurement system in the MAF is the problem? or elsewhere?

The MAF could very well be "aged".

Thank you for the assistance,
John
coach928 is offline  
Old 06-23-2016, 04:47 PM
  #64  
John Speake
Addict
Rennlist Member
 
John Speake's Avatar
 
Join Date: Feb 2002
Location: Cambridge England
Posts: 6,891
Likes: 0
Received 0 Likes on 0 Posts
Default

The fact that the car generally runs better with the pot at 386 ohms even when the blinker says it is wrong, suggests a problem with the measurement.

Have you tried disconnecting the O2 sensor and adjusting the pot so the engine idles well and responds OK to the throttle ?

Hi NOX suggests a weak mixture as per our email conversation.
John Speake is offline  
Old 06-23-2016, 05:20 PM
  #65  
coach928
User
 
coach928's Avatar
 
Join Date: Jun 2016
Location: Redwood City, CA
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by John Speake View Post
The fact that the car generally runs better with the pot at 386 ohms even when the blinker says it is wrong, suggests a problem with the measurement.

Have you tried disconnecting the O2 sensor and adjusting the pot so the engine idles well and responds OK to the throttle ?

Hi NOX suggests a weak mixture as per our email conversation.
I made the Blinkr after our email conversation. The car runs well and idles well with MAF pot at 2 ohms, not so well at 380 ohms. I will try disconnecting O2 sensor and adjusting to confirm.
coach928 is offline  
Old 06-24-2016, 05:14 AM
  #66  
John Speake
Addict
Rennlist Member
 
John Speake's Avatar
 
Join Date: Feb 2002
Location: Cambridge England
Posts: 6,891
Likes: 0
Received 0 Likes on 0 Posts
Default

Have you checked the basics like fuel pressure and engine vacuum at idle ?

The problem could be a MAF problem, they can suffer a form of thermal runaway where the output will be higher than it should be. This enriches the mixture and would force you to turn down the pot to compensate.

Last edited by John Speake; 06-24-2016 at 05:38 AM.
John Speake is offline  
 


Thread Tools
Search this Thread
Quick Reply: LH 2.2 MAF/CO adjustment LED (85-86 US)


Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: