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  1. #1

    Genesis 1200 FFI with miss

    I have a 2001 Genesis I 1200. At the end of last season the engine began to miss at idle, still had good power. Over the course of the winter I checked some things and found MAG cyl was not firing at idle. Replaced/indexed spark plugs. Checked for spark (ok, but swapped coil w/ another cylinder anyways), swapped injectors with another cylinder (I know they are coded to individual cylinder but should change something regardless), checked compression and was good on all 3 cylinders. Out of ideas I pulled all the cylinder heads and found CENTER and PTO cylinders and pistons severly scored. Figured that ECM was compensating for two damaged cylinders and causing miss in MAG cylinder. Pulled engine and did complete top end and bottom end rebuild/reseal. Bored all .25mm over, boysen reeds. Pressure tested assembled engine 6psi/6minutes. Put engine back in and got it fired up and MAG cylinder still dead at idle. Picks up off idle. Picks up if I dump fuel in throttle body. Pull spark plug and it is wet. Fuel pressure is good (new fuel pump installed as regulator had failed on old one likely causing lean condition killing two rear cylinders). I am out of ideas. Any one care to take a stab at it.


  2. #2
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by jewraffe View Post
    I have a 2001 Genesis I 1200.
    At the end of last season the engine began to miss at idle, still had good power. Over the course of the winter I checked some things and found MAG cyl was not firing at idle.
    Replaced/indexed spark plugs.
    Checked for spark (ok, but swapped coil w/ another cylinder anyways), swapped injectors with another cylinder (I know they are coded to individual cylinder but should change something regardless), checked compression and was good on all 3 cylinders.

    Out of ideas I pulled all the cylinder heads and found CENTER and PTO cylinders and pistons severely scored.
    Figured that ECM was compensating for two damaged cylinders and causing miss in MAG cylinder.

    Pulled engine and did complete top end and bottom end rebuild/reseal. Bored all .25mm over, Boysen reeds. Pressure tested assembled engine 6psi/6minutes.

    Put engine back in and got it fired up and MAG cylinder still dead at idle. Picks up off idle. Picks up if I dump fuel in throttle body.

    Pull spark plug and it is wet. Fuel pressure is good (new fuel pump installed as regulator had failed on old one likely causing lean condition killing two rear cylinders).
    I am out of ideas.
    Any one care to take a stab at it?
    Welcome to Green Hulk!

    Have you checked the stator for proper resistance values? Perhaps one of the coils is going bad, and not providing the correct timing signal at low RPM.

    When you had the engine apart, did you check that the magnets on the stator were still in their correct positions?

    BTW, as far as I know, the EMM on the Fitch injection system is open loop. There is no direct feedback, other than engine RPM relative to the amount of throttle (TPS sensor).

    The EMM will not adjust the mixture to provide more fuel if you improve engine breathing. So the reed change may, or may not, cause lean issues.

  3. #3
    axgrider73's Avatar
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    Welcome to the Hulk!!

    Check all of the wire connections that you can find and pay close attention the grounds. It seems to me that I remember them causing troubles.

    You might also PM Bernie, he is the local injector guru.

    Let us know what you find.

  4. #4
    Bernie's Avatar
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    Did you check the reeds before you put them in ,one might not be sealing very well .
    You say the plug is wet but it runs when you put extra fuel in the throttle body
    Do you have access to an oscilliscope for the other values ?
    Timing light ?If you have one put it on the mag cyl at idle and see if it fires the light if it doesn't .Then lift the rpm until you think the cyl is firing and have the light connected .If it does start to flash we then have to find out why it is having issues .Have you checked the plug leads for resistance ?
    Cheers

    Bernie

  5. #5
    visually checked the reeds when installed boysens. Spent awhile on reeds as the screws they supplied I felt were to short by the time you add the 2 reeds, rev plate, and reed stop. contacted them and they offered to send some longer screws but I ordered some locally. Did not check resistance of leads but swapped between cylinders. I do have an ociloscope and timing light so will play around with that next. Will compare injector pulse widths between cylinders as well. Thanks for the ideas.

  6. #6
    Bernie's Avatar
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    You may be able to do a vacuum test on the throttle body which will test your reed seal .Scopes are great for diagnosing these engines as the signal sources are susceptical to vibration .
    Check the v's at the injector as well as coil pack .You may find that the cyl will fire when rpms are lifted because of the rapid pressure build up off rpm helping the cyl' fire .
    Put the scope on the tps and look at the signal as you bring the revs up .Then do comparison with a static test .Can you let us know the signal .It would be great to be able to post the signals on the test and tips section if you can do it .This will help others in their ongoing Ficht hassles
    Good luck

    Bernie

  7. #7
    Probably won't be until next week that I get at it, but will try and scope as many sensors as possible and post what I can. Until then thanks again to all.

  8. #8
    ph2ocraft's Avatar
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    You're describing classis symptoms of a crankshaft being out of index, have you checked it?

  9. #9
    I checked it in a very crude fashion when the engine was apart (also something I suspected) involving a couple vee blocks and a makeshift pointer. Should have checked it better with a degree wheel and dial indicator prior to disassembly. But I figured it would be have to be out a whack to cause this problem.

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