86 240 DL cold start injector failure symptoms

Discussion in 'Volvo 240' started by David, Oct 17, 2003.

  1. David

    David Guest

    What are ALL the symptoms of a cold start injector failure/problem ?
    I'm guessing that "difficulty starting when cold" is a given, but
    what sort of driveability issues would I see, if any ? At what
    ambient and/or engine temps should it make a difference ?
    David, Oct 17, 2003
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  2. From a point at sea, to the circles of your mind, this is David:
    The answer may vary, depending upon the type of fuel system you have
    (the age of the vehicle is no guide - it varied from territory to

    On a system with K-Jetronic fuel injection (if you are UK based this
    is you, but maybe other places as well) the cold start injector only
    operates when the starter motor is cranking, and even then only for a
    limited time. So if it is failing to open, difficult starting during
    cranking is the only symptom; after that the engine should behave as

    If the cold start injector is sticking open, then you will have all
    the symptoms (to a varying degree) of a rich mixture - lumpy,
    'hunting' idle even when warmed up; black, pungent smoke from the
    exhaust under accelleration; heavy fuel consumption; sooty spark
    plugs; failure of emissions tests - high HC.

    On K-Jet there are a couple of other things to be aware of:

    1) Auxiliary Air Valve. This allows more air past the throttle valve
    for a few minutes during warm-up, similar to a fast idle device (note
    - propely adjusted, the cold idle will not be a fast idle - it should
    maintain the idle at about the normal speed). If this fails, you will
    either have very low idle speed when cold, often leading to stalling
    and the need to keep revving the engine, or too high idle speed when
    warm. Above idle speed, drivability will be unaffected.

    2) Warm Up Regulator. This enriches the mixture during the warm up
    period. Because of the way it works, it normally fails to its enriched
    position, so cold starting and warm-up wouldn't be a problem, but the
    engine would be running rich when warm. In the unlikely occurrence of
    it failing in its 'warmed up' state, then cold starting may be harder,
    and until the engine is warm, idle would be weak and unresponsive to
    the throttle, there would be a lack of power, stalling common.


    Stewart Hargrave

    A lot faster than public transport

    For email, replace 'SpamOnlyToHere' with my name
    Stewart Hargrave, Oct 17, 2003
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  3. David


    Dec 17, 2018
    Likes Received:
    Pretty straightforward. Won't start when below operating temp. Might run rough if it stays open when at operating temperature.
    finnegan, Dec 21, 2018
  4. David


    Jan 9, 2019
    Likes Received:
    My 1993 240 wagon will sometimes not start when weather is wet. Idle is also staying high after start and during driving. Help.
    240Wrick, Jan 9, 2019
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