Camshaft and Crankshaft Sensors--I'M BACK

Discussion in 'General Motoring' started by powrwrap, Mar 23, 2007.

  1. powrwrap

    powrwrap Guest

    My saga is found here:

    http://groups.google.com/group/rec.autos.makers.chrysler/msg/2ce8507d97431792?dmode=source&hl=en

    Here is what has happened since the crankshaft sensor, camshaft
    sensor, and power control module was replaced.

    Vehicle ran good for a couple of weeks, then would occasionally die at
    idle while at stop lights. This would happen perhaps 1 out of 3 days
    the car was driven. At highway speeds it would violently jerk--once--
    while temporarily lighting the Service Engine light. The jerking was
    more consistent.

    I took it back to the dealer that installed the power control module.
    There were no stored codes. They suggested that I replace the spark
    plugs and plug wires and clean the throttle body and fuel system with
    chemicals. They had pulled a spark plug and its gap was at .090,
    should be .050. They said once the plugs and wires had been replaced
    and fuel system cleaned it should take care of it, but if it still
    exhibited the symptoms I should take it back to them.

    I cleaned the throttle body area with 3M Throttle Plate and Intake
    Cleaner. Didn't do a super thorough job since I Ieft the part intact
    and sprayed and wiped with a rag inside the throttle body cavity.
    However, this seems to have stopped the problem with the vehicle dying
    at idle at stop lights.

    Now all that remains is the violent jerk and temporary lighting of the
    Service Engine light. Curiously, this symptom always occurs at the
    same area of my wife's drive to work. In fact, she says it is
    predictable and anticipates when it will happen. She's rarely
    disappointed.

    I don't think it is elapsed time the engine has been running, nor is
    it distance traveled. I'm thinking it's related to engine temperature.
    But what? I doubt this is spark plugs causing this problem. One jerk
    at about the same time after engine startup and momentary flash of
    Service Engine Light. Again, when the dealer hooked up the scan tool
    there were no stored codes.

    So, any ideas? Temperature related problem? Some sensor hiccuping?
     
    powrwrap, Mar 23, 2007
    #1
  2. powrwrap

    bllsht Guest

    Not sure if it was on '97 models, but there was a TSB that dealt with
    a problem like this. It involved removing the knock sensor because it
    would cause the PCM to reset while driving.
     
    bllsht, Mar 24, 2007
    #2
  3. powrwrap

    powrwrap Guest

    Hey thanks! I'll research it...
     
    powrwrap, Mar 24, 2007
    #3
  4. powrwrap

    powrwrap Guest

    Can someone that has access to Chrysler technical service bulletins
    please post #19-34-98? I believe it is dated 11/27/1998. I found this
    while searching Yahoo Groups. It may contain the solution to a long
    running problem. Thanks.
     
    powrwrap, Mar 24, 2007
    #4
  5. powrwrap

    maxpower Guest

    not a good number
     
    maxpower, Mar 24, 2007
    #5
  6. powrwrap

    maxpower Guest

    18-34-98 is a TSB that requires disconnecting and taping the wire of the
    knock sensor for a symptom you are describing BUT this only occurs if the
    Module is resetting itself back to zero and all the learn values resets. A
    scan tool is required to determine if this is what is happening.

    Glenn
     
    maxpower, Mar 25, 2007
    #6
  7. powrwrap

    maxpower Guest

    18-34-98 is a TSB that requires disconnecting and taping the wire of the
    knock sensor for a symptom you are describing BUT this only occurs if the
    Module is resetting itself back to zero and all the learn values resets. A
    scan tool is required to determine if this is what is happening.

    Glenn
     
    maxpower, Mar 25, 2007
    #7
  8. powrwrap

    bllsht Guest

    It doesn't take a scan tool to determine if disconnecting the knock
    sensor eliminates the symptoms.
     
    bllsht, Mar 25, 2007
    #8
  9. powrwrap

    maxpower Guest

    No it doesn't. But the OP stated that it happens sometimes, a scanner would
    have determined that the PCM went into a reset mode and cleared all learned
    values

    Glenn
     
    maxpower, Mar 25, 2007
    #9
  10. powrwrap

    philthy Guest

    find a shop that has a bore scope and have the flex plate checked for cracks/breakage and jambed
    into place
    i have one if you are near brighton michigan
     
    philthy, Mar 25, 2007
    #10
  11. powrwrap

    bllsht Guest

    Considering the MIL gives a flash and there are no stored codes, I'd
    bet the PCM is resetting. Another trip to the dealer that didn't even
    bother checking for TSBs, even after repeat visits, is not what I'd
    recommend.

    I'd disconnect the knock sensor and drive it. If the symptoms stop,
    then it was resetting because of the knock sensor. If the symptoms
    remain, a scan tool (in the right hands) would be in order.
     
    bllsht, Mar 25, 2007
    #11
  12. powrwrap

    powrwrap Guest

    I might try that, but how would a cracked flex plate cause the
    symptoms to occur at almost the exact same time every time the car is
    driven?
     
    powrwrap, Mar 25, 2007
    #12
  13. powrwrap

    powrwrap Guest

    Hmmm...so the scan tool can determine if the PCM is resetting back to
    zero and erasing any stored codes? If so, shouldn't the dealer have
    told me that the reason the PCM doesn't have any stored codes is
    because it's been resetting itself?
     
    powrwrap, Mar 25, 2007
    #13
  14. powrwrap

    powrwrap Guest

    Well, you just answered my first question that I posted about 30
    seconds ago. A scanner can tell if the PCM went into reset mode.

    Now I wonder if the dealership knows this and sold me a PCM that I
    really didn't need.
     
    powrwrap, Mar 25, 2007
    #14
  15. powrwrap

    powrwrap Guest

    Sounds like a reasonable suggestion. Can anyone give any reasons why I
    shouldn't disconnect the knock sensor?
     
    powrwrap, Mar 25, 2007
    #15
  16. powrwrap

    bllsht Guest

    A good scanner can give the user the info. It's up to the user to
    interpret that info.
    If I remember correctly, you were still getting cam or crank sensor
    faults before the PCM was replaced. You haven't mentioned any since it
    was replaced. Could be you've had 2 different problems.
     
    bllsht, Mar 25, 2007
    #16
  17. powrwrap

    powrwrap Guest


    Yes, using the Co-Pilot device the stored codes were simultaneous cam
    sensor AND crank sensors faults. Since I had already replaced them
    they suspected the wiring between these sensors to the PCM or the PCM
    itself. The wiring checked out OK, so that left the PCM as the most
    likely source of the trouble.

    I suppose it could be that I've developed another problem since the
    PCM was replaced that is causing the PCM to reset itself. When the
    dealership said there were no stored codes, I wonder if they checked
    to see if the PCM was resetting and clearing them out. I guess I'll
    call them tomorrow and ask about that and also the TSB.
     
    powrwrap, Mar 25, 2007
    #17
  18. powrwrap

    maxpower Guest

    Hmmm...so the scan tool can determine if the PCM is resetting back to
    zero and erasing any stored codes? If so, shouldn't the dealer have
    told me that the reason the PCM doesn't have any stored codes is
    because it's been resetting itself?


    Like it was already posted, a tool is only as good as the person using it,
    but yes it can see that everything has been reset. disconnecting the knock
    sensor if so equipped wont hurt, but not your problem. The TSB you are
    referring to is a one time occurrence while driving, it WILL NOT cause
    severe bucking or constantly surge. What you would experience if this was
    the problem with a knock sensor would be a quick surge as the PCM reset
    itself. and then run fine until a next start up.

    Glenn
     
    maxpower, Mar 26, 2007
    #18
  19. powrwrap

    powrwrap Guest

    This is exactly what happens. One sudden jerk, flash of the Service
    Engine Light, then everything back to normal driving. Next day, same
    thing, at about the same distance/time traveled.
     
    powrwrap, Mar 26, 2007
    #19
  20. powrwrap

    aarcuda69062 Guest

    You could have disconnected the knock sensor in the same amount
    of time it took to post.
     
    aarcuda69062, Mar 26, 2007
    #20
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