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Thread: Engine cutting out

  1. #1
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    Engine cutting out

    So I am new to the forum. I just purchased a 1987 XJ6 SIII base. It has a case of cutting out when driving. It has a slightly rough idle, but not bad. I drove it for a week, no issues, now this cut out has started. To troubleshoot, I've done the following:

    Repaired vacuum leaks in the air pump and throttle body.
    Replaced spark plugs
    Replaced ignition coil and resistor
    Replaced Distributor cap and rotor
    Ran through 2 full tanks of gas
    Replaced the fuel filter

    Before I go further, I thought I'd check in with the experts My Dad always advised me to keep it simple and diagnose Fuel, Spark and/or Air. So, I am thinking it might be worth replacing the fuel pump. Electrical, i don't know what is left unless the distributor is having issues. Air, I don't see anything.

    Any advice would be very appreciated and helpful.

    Thank you and I'm looking forward to this next journey.

    Rob

  2. #2
    Senior Member Fraser's Avatar
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    Did you sort this out at all ?
    I had a Series 3 and suffered from cutting out when driving and on one ocasion I was on the outside lane of 3 overtaking up a steep hill when it happened. Brown deposit in pants time !! So I then decided this problem had to be licked or else !! I found out that it was the contacts in the MAF that pass volts to the fuel pump relay. These are really TINY and over time the springiness of them reduces so cutouts occur. It is even mentioned in a guide to the XK engine here in the UK (AJ6 Engineering). SO once I had removed the MAF cover and bent the contact carriers to bring back some spring pressure on the contacts, and also cleaned them, I had no more trouble.

    http://www.jagweb.com/aj6eng/
    Fleet manager (!!) of: -
    XJ6 Sovereign 2007
    VW New Beetle 2009
    MG Midget 1500 1977
    MG TF 135 2010

  3. #3
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    ~Engine cutting out

    I haven't had success YET. This one will be solved! I tried your suggestion in the MAF connections. I also resealed the MAF as it had a vac leak. So far, I've:
    - replaced the ignition coil
    - replaced spark plugs
    - replaced fuel filter, pump and cleared lines
    - checked flow and condition of fuel from the tanks
    - replaced the fuel pressure regulator
    - Replaced distributor cap & rotor
    - ran with bypass on coolant temp sensor
    - fixed various vac leaks
    - checked vac to distributor (~10lbs - though it does not seem to effect advance when removed)
    - replaced exhaust gasket above the O2 sensor

    Its strange - it runs fine cold, and stalls (as if the engine is completely cutting out) when warm (operating temp). It also has a slight backfire (as if running lean).

    I have not looked at the injectors as I assumed that would mean a miss rather than cut out.

    I can next check timing and valve adjustments. not sure this would do much though other than improve idle/running.

    This one is a bugger. I'm not as familiar with sensors, diagnostics for signals of the electrical system. Running out of ideas - but know it's certainly solvable.

  4. #4
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    SOLVED! It was the MAF. I fiddled with it and fiddled with it and just decided to replace it. Found a rebuilt on online and wha-la! Runs like a dream.

    While in the air intake system, I gapped the butterfly, replaced the rubber connecting hoses and set the timing. Very happy to have this solved.

    Thanks for the help Fraser!

    RN

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  6. #5
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    Glad to know that you have solved the problem & thanks for the feedback.
    Cheers

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