Announcement

Collapse
No announcement yet.

323i AFM position at idle

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    323i AFM position at idle

    Hi, I picked up an 84 euro spec 323i a couple of weeks ago in a semi running condition. The car will start, jump to 2k, climb to 2500 and then surge between 1000 and 1500 for about 10 sec before stalling out.

    So far I have checked:

    Fuel pressure
    Compression
    AFM resistance
    Aux Air Valve
    Vacuum Advance
    Spark

    All of which have been good

    About a week ago it did it’s normal start but that time it didn’t die and ran long enough for me to take it around the block. (Long enough to find out the diff is barely attached to the chassis)

    The only weird thing I can see at the moment is that while it’s sitting around 1000-1500 the AFM is almost halfway open and I was wondering if this is the normal position?

    It does seem to be a different AFM then US Motronic cars got but I’m not sure wether the spring pressure would be different.

    Sidenote: I accidentally found that if you pull 2 of the injectors and/or plug wires so it’s running on 4 cylinders it runs fine at like 1200, no surging. Not sure what this means
    Tags: None
    #2
    Id look for vacuum leaks. Unsure of vane position in relation to idle..

    I was up above it, Now I'm down in it ~ Entropy - A Build thread.
    @Zakspeed_US

    Comment

      #3
      Rolling idle is an indication of an air leak after the AFM. Check things like the b!tch tube o-rings etc.
      john@m20guru.com
      Links:
      Transaction feedback: Here, here and here. Thanks :D

      Comment

        #4
        After a lot of fettling I believe I found the issue, for some reason the Aux Air Valve seems to be letting air through, enough to hold the idle at 3000 with enough fuel (It was surging because it was getting 3k worth of air and only an idle’s worth of fuel) even though it worked exactly as it should off the car. After disconnecting that line and plugging everything up, I can now adjust it to idle properly.

        On a separate note, how loud should the valvetrain noise be? This is my first m20, and I know from my e28 the sohc lifters are not quiet but it seems a bit ridiculous

        Thanks for the replies

        Comment

          #5
          M20's tick that's what they do. But the valves do need to be adjusted every so often. 15k miles or so.

          88' Seta 2.7i Zinno

          https://www.r3vlimited.com/board/for...430-my-88-seta

          Comment

            #6
            ...and if they aren't adjusted every 15k or so, they get flat spots on the eccentric adjusters, so that when readjusted, they make even MORE noise.

            If it's stupid- loud, and you're sure it's on the tight side of correct, see if you have flats. Last I looked, the adjusters were still pretty
            reasonably priced. Buy a couple extra nuts, too, as sometimes they strip from overtightening.

            t
            now, sometimes I just mess with people. It's more entertaining that way. george graves

            Comment

              #7
              t,

              They seem to be quieter when you replace the flat spotted eccentric adjuster?

              I was up above it, Now I'm down in it ~ Entropy - A Build thread.
              @Zakspeed_US

              Comment

              Previous template Next
              Working...
              X