Is it the rpm sensor or the cam location sensor on my 94 850

Discussion in 'Volvo 850' started by byrocat, Aug 25, 2005.

  1. byrocat

    byrocat Guest

    Standing beside the driver front wheel, I look at the engine block.
    Just to the right and above the distributor is a round cover held on
    with two screws, with a single wire that goes towards the distributor.

    Is this the cam location sensor that you get a heat failure with (car
    stalls and then will not start until it all cools off)?

    My copy of Haynes has the illustration (5.47 on page 2B-6) That has the
    cam sensor (14) line pointing down toards the distributor, while
    there's a line pointing at where the sensor is supposed to be that says
    that its the rpm sensor (16).

    To top things off, I don't have a link to thae "brick" website that
    deals with repairs so I can figure out what I need to do.

    Also, has anyone had any experience with a used cam sensor replacing
    the one that's heat-sensitive. I'm looking at about 250 Canadian for a
    new one. (OUCH! -- <:-o) !)
     
    byrocat, Aug 25, 2005
    #1
  2. byrocat

    Tim.. Guest


    Yes, this its the Cam Position Sensor (CPS) located on the exhaust cam
    (dissy on inlet cam).

    On any car with Motronic or Fenix management (not LH 3.2) i.e. those with a
    single ECU for engine control, failure of the CPS will cause failure to
    start.

    Be careful to distinguish from a faulty crank angle sensor on the
    bellhousing as this will also cause a no-start.

    Arm yourself with a can of freeze spray or brake cleaner, and when it next
    dies, spray one sensor at a time to cool it off and attempt a restart. See
    which one needs to be cool for the engine to start.

    Tim..
     
    Tim.., Aug 25, 2005
    #2
  3. byrocat

    byrocat Guest

    JUzt in case someone is giving this a quick scan.I've got two distinct
    non-run behaviors that seem to be possible the same item.

    If the car has been sitting in direct sunlight for a couple hours, I
    can make a trip and get out to do some shopping. The restart for the
    trip home results in a almost-run burble and then everything lights up
    and I now have to go for a can of pop and then more shopping until
    everythign cools down.

    The second is when I'm in traffic and at an idle, burble and then dead.
    Sometimes, an immediate restart works and sometimes I'm there for a
    while.

    However, lugging around a can of comressed air and blasting the sensor
    plate and area around and giving things a retry is a good idea.

    Of course, Murphy's Laws of Testing will apply: when ready for a
    failure to diagnose the reason for the failure, the failure will not
    occur.
     
    byrocat, Aug 25, 2005
    #3
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.