1993 Volvo 850 with 256 kmi Stalled and will not start.

Discussion in 'Volvo 850' started by Mark Barron, Aug 14, 2009.

  1. Mark Barron

    Mark Barron Guest

    The car was driven a couple of miles. It was behaving well
    but had a fairly rough idle. The car came to a stop, the accelerator
    was press, the car began to move and then stalled and has not started

    The plugs are new and have good spark
    The fuel rail has 43 psi. Pressure bleeds away overnight.
    The pressure reaches 43 psi very quickly.

    If i crank the engine, the plugs do not appear to be wet.
    If I stick in a twist of paper towel in the spark plug hole
    in place of a plug, the towel does not appear to be wet after
    a 5 second crank. I can however smell gas then.
    -The resistance of the VSS speed sensor is 1740 ohms instead of
    the expected 200 ohms.
    -There is 11 volts between CMP sensor term 3 and ground (10 V is expected)
    -CMP terminal 1 to ground is 0 ohms, as desired
    -when I check the power stage control signal (terminal 4 to ground)
    I get 0.2 volts, where I read I should have 0.7-1.3 V (what does this mean?)

    I have an 98 S70 to pull parts from.

    1. I have a diagnosis write up(named "BasicTesting-Turbo.pdf" for a
    Volvo and it says to use
    a breakout box( I don't have one) for a CMP sensor test, that is
    "check between BOBox terminal 20 and 4 and Operate the starter
    voltage should vary between 0-5 volts"
    Would the terminals 20 and 4 correspond to wires labeled 20 and 4
    in a Haynes Volvo 850 wiring diagram?

    2. Can a ECU from a 98 s70 go in an 850? Roughly what would I have
    to pay for an ECU?

    3. What do I do next? I wish I had a better write-up.

    Thanks for reading.
    Many Thanks, Mark
    Mark Barron, Aug 14, 2009
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  2. Mark Barron

    James Sweet Guest

    Do you know if you're getting a spark? That's the first thing I'd check,
    if you have a spark, then the problem is probably fuel, but if you smell
    gas, I'm leaning towards ignition.
    James Sweet, Aug 15, 2009
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  3. Mark Barron

    Mark Barron Guest

    I removed the air filter assembly and shot Starter Fluid into the
    intake. It did not fire although the engine turned over well.
    I quess I will swap CMP sensor from my 98 s70.
    Thanks, Mark
    Mark Barron, Aug 15, 2009
  4. Mark Barron

    Mark Barron Guest

    I have spark, but even when I squirt starter fluid into the intake
    directly, I can not get the engine to even cough. How can that be?
    I will check again to insure that I still have spark.
    Thanks you for replying.
    Mark Barron, Aug 17, 2009
  5. Mark Barron

    James Sweet Guest

    Is there compression? Timing belt didn't break did it?
    James Sweet, Aug 17, 2009
  6. Mark Barron

    Mark Barron Guest

    Belts are good, I replace the timing belt last summer, I honestly have
    not checked compression will do tonight.
    I think I may have found the problem. I tested voltage at 3 of the five
    injector connectors. The wires are green and white. When I turn on the
    ignition, BOTH wires have battery voltage , +12.85. Is this right?
    Does one of the wires get cyclically grounded by the ECU and thereby
    cause the injector to fire? Or is this situation indicative of wires
    crossed? I am not yet sure where the green and white injector wires run,
    I am guessing to the ECU. Let's say for argument, that the cause of the
    no start is the fact that the injectors don't fire. If I find 12.8 at
    the injectors then what is left to explain the injectors not firing? --
    The ECU right?
    Thanks for reading.
    Mark Barron, Aug 17, 2009
  7. Mark Barron

    James Sweet Guest

    Generally speaking, yes, one wire receives +12V and the other is pulled
    low by a power transistor in the ECU. The pulse is brief though,
    especially at start/idle. You really need to connect a test light across
    the injector connector and crank it, if all is well the light will
    flash. Sometimes you can also hear the injectors tick but the starter
    can drown it out.
    James Sweet, Aug 18, 2009
  8. Mark Barron

    Mark Barron Guest

    The timing belt did not break. I got the following compression readings
    1-4. Battery was too low to get #5.
    Mark Barron, Aug 18, 2009
  9. Mark Barron

    Mark Barron Guest

    I will be on the hunt for what I think is called a noid light.
    Mark Barron, Aug 18, 2009
  10. Mark Barron

    James Sweet Guest

    That's the tool designed for the job, but it's not the only way to do
    it. In a pinch you can take one of those wedge based bulbs used as side
    markers on a lot of cars, bend down the wire contacts and poke them into
    the injector connector. Another approach is a regular automotive test
    light, the sort that looks similar to a screwdriver with a sharp tip and
    a bulb in the handle. Poke some thin wires into the contact sockets on
    the injector connector and connect the test light there.
    James Sweet, Aug 18, 2009
  11. Mark Barron

    Mark Barron Guest

    the IAC does buzz. I have ordered a Fuel Injector Main Relay, circa $29,
    since I don't see anything wrong with the wiring. I am so grateful for
    your input. I will advise.
    Mark Barron, Aug 20, 2009
  12. Mark Barron

    James Sweet Guest

    Did you check the output of the injectors? I'm not sure where the relay
    is wired in those cars, but normally that just serves to control power
    to the whole system, a relay is much too slow to do the actual injector
    pulsing. Don't just throw money at it, diagnose.
    James Sweet, Aug 20, 2009
  13. Mark Barron

    jimmy Guest

    Check the distributor cap to make sure there are no cracks.
    I put a brand new one on (aftermarket) that had a crack. Caused
    rough idle and dying at stoplights like it had bad gas. Drove me
    to drink b4 an excellent mechanic in Austin, Tx (hey Troll!)
    finally figured it out ;-) Good luck!
    jimmy, Aug 20, 2009
  14. Mark Barron

    mejbarron Guest

    When you say, 'check output of injectors' you must mean pulling
    injectors to see gasoline
    spray right?

    I have replaced the distributor cap. I thought the distributor rotor
    looked ok.

    I tried again to start the 850 with a fully charged battery. A2 and A6
    totally empty of codes both before and after the try. The car did
    turned over
    well but did not even cough. Half way through the 20 second crank I
    tried some
    Starter fluid into the intake. The Air Filter assembly was removed.
    and the
    MAF sensor disconnected. I was thinking about the possibility that the
    being good but the wires to the same being bad. Below are the readings
    I got.

    Fuel Injector Main Relay Connector 4-Female .
    Wires going out below page
    / \
    | 87 30 |
    | |
    | 85 86 |
    | |

    87 Thick Green
    30 Thick Red
    85 Thin Brown
    86 Thick Red

    With Ignition Off

    Wire To Grnd Volt To Grnd Ohms
    87 0.0 1590
    30 12.6 16 Meg
    85 0.0 infinite
    86 12.6 16 Meg

    With Ignition ON

    87 0.0
    30 12.6
    85 0.0
    86 12.6

    DVM readings done later with weak battery at 12.6 Volt
    mejbarron, Aug 21, 2009
  15. Mark Barron

    mejbarron Guest

    Hey guys I think I found something.
    The 1590 ohms at pin 87 did not seem right.
    I tested the resistance at pin 87 with the
    ignition turned on, it read 2.6 Mega Ohms.
    I don't know the specs for the fuel injector
    current, but it would be a very tiny current
    flowing at 12 V through that kind of resistance
    - or am I looking at this wrong?
    Where do I find the other end of the wire at pin 87
    of the main fuel injector relay?
    Thanks for much for reading.
    mejbarron, Aug 22, 2009
  16. Mark Barron

    bassdiva Guest

    My 850 would do this occasionally, and the only way I found to get it going
    was to turn the key and crank the engine until it did start. this could
    take quite a long time, and I am talking several minutes not seconds. I
    always thought the battery would give out but it never did, you just got to
    keep your nerve
    bassdiva, Aug 24, 2009
  17. Mark Barron

    James Sweet Guest

    That sounds like the relay coil resistance, I don't know the pinout off
    hand, but if that's what it is, then that's about right.

    With the ignition turned on there is voltage there, so if you try
    checking resistance you'll get a meaningless value. In this case it
    sounds like your meter is effectively pegged.
    James Sweet, Aug 25, 2009
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