Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E28 (1982 - 1988)

E28 (1982 - 1988)

Reply
 
Thread Tools Display Modes
  #1  
Old 06-07-2013, 07:54 PM
ckplays ckplays is offline
Registered User
Location: southern cali
 
Join Date: Jun 2013
Posts: 1
Mein Auto: 528e
O2 sensor causing problems

I've got a 1986 528e that's giving me problems. My friend and I just had the whole engine apart to change the head, #5 piston, and the broken timing belt that caused all the destruction. Now that it's all back together, the engine runs great... but only with the O2 sensor disconnected.
Here's a list of the things we've tried:

- Replaced O2 sensor with a BRAND NEW one. (No improvement)
- Cleaned and tested throttle position sensor (just two switches, not a potentiometer)
- Double and TRIPLE checked for vacuum leaks and I absolutely assure you all that there are NO VACUUM LEAKS!
- Ultrasonic cleaned and tested all fuel injectors (they are fine)
- New fuel filter
- No kinks or restrictions in fuel line
- Tested idle air bypass valve and checked adjustment (its fine)
- While motor was apart all valves were checked for leakage and rocker clearances set to .012" as specified.
- New spark plugs, wires, and cap. Has a healthy spark.
- Compression check shows all cylinders exceed the minimum spec 144psi (180-200)

Once again, the engine runs great with no O2 sensor. But with it connected the engine runs extremely lean and barely has enough power to move the car at low-mid rpms. It picks up a bit of power at 4000+ rpm, but not much.
I would just run it with the O2 off, but it needs to be smogged now and (although I do know a guy), I want to do it LEGALLY.

Any idea what is at fault?
Reply With Quote
Ads by Google
  #2  
Old 06-07-2013, 10:33 PM
catso's Avatar
catso catso is offline
catso
Location: Chicago
 
Join Date: Dec 2009
Posts: 2,854
Mein Auto: 2000 323i, 1988 528e
As a guess, I'd suspect the Air Flow Meter.
__________________
Don't be gormless; get some gorm!
![/I][/FONT]
Reply With Quote
  #3  
Old 03-03-2014, 04:25 PM
zackkcaz zackkcaz is offline
Registered User
Location: Ohio
 
Join Date: Feb 2009
Posts: 1
Mein Auto: 88 535i
Bump!

What was the issue??

AFM? o2 sensor?
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E28 (1982 - 1988)
Today's Posts Search
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



Forum Jump


All times are GMT -7. The time now is 09:48 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms