Poor acceleration. Vtec feels like it is partly working.

Discussion in '6th Generation 2002-2013' started by afinepoint, Nov 14, 2011.

  1. afinepoint

    afinepoint New Member

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    VTec not operating properly. The pull is not at 6400rpm as before but closer to 6600 rpm and is weak. A vibration begins around 5000 rpm and continues well above 6000. There is also a loud rattle when the bike crosses over a rough surface. Regarding the Vtec per the manual the system engages whenever engine temperature is over 149 and rpm is 6800.

    The problem could be the ECT, ignition pulse generator, ECM or spool valve. Oil level is good.

    Will troubleshoot when time off makes it possible. Just thought I would thow it out there should another have experienced this.

    I did see a post years back but I wanted to get fresher feedback.

    Reg
     
  2. Meatloaf

    Meatloaf New Member

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    Do you by chance have any other way of monitoring the actual RPM other than the tach? It is possible that the teach is off a tiny bit, thus why you are seeing VTEC engage at around 6600RPM.
     
  3. TOE CUTTER

    TOE CUTTER Mullet Man

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    Took my manual to work so I do not have it right now, is there a test port for oil pressure past the spool valve? Thinking that is the best place to check for proper V-tec actuation.
     
  4. stoshmonster

    stoshmonster New Member

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    Nope,don't see any external oil pressure test port anywhere Toe.

    [​IMG]

    Might wanna test the spool valve itself. It's basically an on/off switch,either it's working or it's not.
    Here's some additional info for a coupla other things you might wanna check too.

    [​IMG]

    Just a heads up,there's a filter screen under the spool valve. Part number 7.

    [​IMG]
     
  5. afinepoint

    afinepoint New Member

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    I am beginning to think this is not a VTEC issue but VTEC is a victim. Performance is poor across the band. The second set of valves appear to be opening but the increase in acceleration is so anemic it seems like they are not fully there.

    As I stated there is a distinct clunking rattle from beneath the gas tank cover (top of engine) that started with this problem. Something is loose.

    I think that something has to do with fuel or air delivery. Mileage is up because the engine HP is down. It seems fuel or air is being restricted.

    More to come.
     
  6. afinepoint

    afinepoint New Member

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    Nothing found by the shop. The tech neither heard the rattle nor found there is a power loss. He said the bike felt like other VFRs and is running on all cylinders. He did not shake the bike over a bumpy surface such as tracks but only over street bumps. I told him the rattle is only heard when I zip over tracks or other such bumps at speed.

    We talked at length and he feels the problem could be bad fuel or a clogged injector.

    I added some cleaner and will run a couple of tankfuls through. As I left I could still feel the reduced peformance. The surge as the Vtec ativates is all but gone.

    He has no idea what could be causing the rattle but will do a more detailed inspection if I wish.

    The good news is the total for the bill was $0.00.

    There are honest people out there. Not necessarily expert troubleshooters but at least honest.

    The saga continues.
     
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