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    What have I done?

    A couple of weeks ago I performed a home compression test on my 325eta, put everything back where I found it, and immediately since I experienced these problems I've never had before:

    -RPMs will drop to 0 at idle occasionally, will never die if I give it gas.
    -Occasional chunky / choking sound at idle (no throttle): it sounds as uncomfortable as an M20 with a crazy cam. Sometimes it flips the switch and idles inaudibly at 800 rpm.
    -Will misfire and lag at low RPMs in 1st. It's strange, it holds back almost all of its power with a fast blipping noise when it happens.

    What bothers me is that this happened immediately after the compression test and feels very clear that it caused these issues. I wouldn't put it past clogged injectors / fuel filter, and fuel pressure is low, but I don't think those are the most likely causes.

    It has-

    New cap / rotor / plugs, gapped plugs to .028 inch. Torque may be suspect but felt similar to the previous setting.
    Tried multiple ECUs- one stock new one w/ Mark D chip misfires a bit more but runs better outside of that.

    It ran very smoothly before most of the time, outside of alternating between closed and open loop. Potential issues not mentioned so far are a pretty beat up conical air filter, intake manifold funny spot that looks like it was welded over or something. Coolant temp sensor gives me jumpy readings. One of the spark plug threads is painfully beat up. Compression is 5 180's and 1 150 but didn't seem to ruin anything before.

    I've tried unplugging and plugging back in the wires. Where should I start from here? I have plenty of time as it's not needed for transportation and I'm ok with taking it easy until I save up for a full rebuild. Would feel amazing to get it running smoothly again and drive it everywhere though. The other family's 80s box (8v 190e) is having a similar issue and that would be fun to put in the past too.

    Thanks!

    #2
    Maybe the wires are bad. They might have separated when you pulled them to change the plugs. Borrow a set to see if your problems go away.

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      #3
      what things exactly did you touch to do the test?
      89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

      new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

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        #4
        Bumped the crank position sensor(s) or their connectors?

        Bumped one of the 2 or 3 other connectors that those signals go through?

        Seems to me you've probably nudged something that was already marginal,
        or it went back together marginally.

        Maybe a ground?

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

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          #5
          I took out main and fuel pump relay, wires and plugs and the coil wire out of the distributor. Those things I've tried plugging in again, haven't paid attention to crank sensors though, I'll give those a shot.

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            #6
            Update: replaced the old un-shielded no name intake with a KAmotors carbon fiber shielded K&N and it's been absent of this odd running problem for about 100 miles. Sounds silly, but,

            -I would drive it to school warming it up, park it, and come back within 2 hours, and that would be one of the situations where it would start dying every single time. The heat under the hood may have spoiled the air to an extent where the computer had forgotten what to do with all the hot air going through the intake. True or not, the result I'm getting now is a sleeping baby idle @ 750 rpm from the start.

            -While my coolant reading is still fidgety occasionally it is no longer alternating between a 1000 rpm and 750 calm rpm idle after warming up.

            In any case this car has been breaking every part I've installed improperly while graciously accepting re-dos and it's adorable that it's teaching me lessons like accepting only proper cold air.

            Comment


              #7
              Originally posted by uturn View Post
              Maybe the wires are bad. They might have separated when you pulled them to change the plugs. Borrow a set to see if your problems go away.
              this actually ive had issues with before. the wires were so old that they either didnt "click" to grab onto spark plug. or they were like an old headphone where you turn the AUX port and it would either work or not. i ended up just replacing them after putting new spark plugs in.

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                #8
                Issues resolved:

                1000 rpm open loop idle- Coolant temp sender wire is broken in half
                Misfire- Spark plug wire slides off distributor very easily

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