2001 sc1 Cyl 1 misfire

Discussion in 'General Motoring' started by Scott, Jun 6, 2007.

  1. Scott

    Scott Guest

    my wife's 2001 sc1 is idleing very fast, 1800 rpm, and using my
    brother's obdm2 computer, I got a "cylinder 1 misfire". Anyone got a
    clue for me to follow before I take it in?
    Scott, Jun 6, 2007
  2. Scott

    Bob Shuman Guest

    Your really do not provide enough description of any other related symptoms
    to make a diagnosis, but if you want an educated guess, mine would be the
    Coolant Temperature Sensor since these are known to fail and when they do
    they cause the engine to run rich. This is a cheap part (~$10) and takes
    about 5 minutes to swap out. Other possibilities include a vacuum leak
    possibly from a cracked hose or a severely clogged air filter. Good luck.

    Bob Shuman, Jun 7, 2007
  3. Scott

    philsearch Guest

    My wife's 2000 SL1 has the same thing I think.....runs fine, then put
    in 'park' and idle jumps to 1800-2000. Does not always behave like
    this though--only sometimes.
    Also, some sputtering noises out tail pipe (usually in idle).
    Some days 'check engine' light is on & other days it's not. Had this
    checked and got the same code (301).

    Also I don't know if this is related, but, car sometimes shifts VERY,
    VERY hard into reverse. This is not just when idling high.....normal/
    low idle....1-2 second pause after shifting....then shifts hard. This
    problem started before the idling problem.

    Any help or advice is GREATLY appreciated!!!!
    philsearch, Jun 7, 2007
  4. Scott

    Scott Guest

    Yes, I also have some exhaust sputtering. I have so far regarded it as
    an isolated issue, unrelated to my before mentioned problem, but maybe
    it's part of the problem.
    Scott, Jun 8, 2007
  5. Scott

    Bob Shuman Guest

    Some thoughts you can consider:

    Pull the spark plugs and take a look at their condition. If they are
    covered in carbon/soot, then the engine is running rich. Either clean them
    using sand paper and re-gap them correctly, or replace and gap w/new plugs.

    Also make sure that the coolant gauge starts cold and goes to above the
    middle mark when hot.

    Replace the air filter if it has not been done recently, and also thoroughly
    clean the throttle body using TB cleaner and an old toothbrush. Make sure
    the throttle body choke plate seats cleanly all the way around.

    Bob Shuman, Jun 8, 2007
  6. Scott

    Scott Guest

    Thanks for your advice. I cleaned the throttle body really well, and
    that did help a little. RPM's became steady at about 1500-1600 instead
    of approx 1800. coolant gauge never gets up to the middle point, so I
    installed a new coolant temp sensor. The rpms initially (for about a
    minute) were a little lower, 1400 or so, but are consistently even
    higher now, 2000 rpms, and not so steady. the range is from about 1800
    to 2100, mostly right at 2000. also, I ran the engine for awhile
    bypassing the air filter with the same results, so it isn't the filter
    either. Not sure where to go from here. also, do I need to reset the
    onboard computer faults, or would the computer do that itself?
    Scott, Jun 10, 2007
  7. Scott

    philsearch Guest

    LOL...I got the same thing, Scott.
    Thanks for the advise, Bob.....I had just replaced my plugs 4 weeks
    ago, so I checked them & they were fouled. Cleaned & re-gapped them.
    Pulled throttle body off and cleaned it really well. Replaced IAC.
    Now Car starts at 3000 rpms and immediately begins to drop until it
    hits 1900. I let it run 10 -12 minutes.....it climbed up to around
    My coolant gauge has never reached midway point either.
    I disconnected battery for 30 minutes to try to reset PCM....does that
    do it?
    Isn't there a way to reset it? Could this problem just be the PCM
    still trying to compensate for the earlier problems and needs to be
    Thanks again guys.
    philsearch, Jun 10, 2007
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