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Bike running rough

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by peter-reebok, Jul 27, 2007.

  1. Suzuki M50 (800cc cruiser) 8 months old, 11,500 klms.

    Bike obviously wants to be traded - it is running shite!

    Started with a rough idle sometimes.
    Then a hesitation on constant throttle.
    Then it cut out at the lights.
    Then the FI light started coming on.

    Removed the TFI unit, adjusted the idle, but starts running bad after 10 minutes.
    The Suzuki EFI system doesn't store codes, so when it is restarted, it just resets itself.

    Has done 11500 klms, svc due at 12000 klms.
    The spark plugs are due to be replaced at that svc,

    My thoughts at the moment are.
    1. plugs
    2. TPS sensor
    3. O2 sensor

    Any other suggestions?

    Off to the dealers on Monday - lets see if I can get any answers!
  2. TPS sensor, or poor spark caused by lead, coil/CDI etc
  3. Thanks Tweet,
    Your last advice was spot on, so you carry some weight!
  4. No problem,
    Difficult to diagnose without seeing it.

    Take a look at the plugs, see what they indicate, could be overfuelling.

    Sometimes, coolant temp sensor (if it is in fact watercooled) can fault, telling the ecu that the bike is cold, and thus keeps the fuel/air mix rich causing overfuelling, and fouled plugs.
  5. The frustrating thing is that it has fault codes, but doesn't hold them.

    You need to recreate the problem with the check switch installed, and the interpret the code.
    If you restart the bike,(to get home or dealer) it resets the codes. So, to get it to the dealer, you reset the code!. Then he can't diagnose the problem properly, cause the code isn't visible.

    Will leave the bike with the dealer on Monday - no real choice.
    Tomorrow I will check all the connections, just in case that is the answer.
    Was planning on new plugs in 2 weeks, have already bought them, will gap em, and put them in tomorrow.
    Got a dose of the flu as well, so cant be fagged doing much.
  6. Had the bike at the dealers since Monday, and have just been getting madder and madder.
    They have done nothing, and suggest they MAY be able to look at it soon.
    Spat the dummy big time, and they fitted the diag plug (that displays the codes) and dropped the bike at my place. I rode it for 15 minutes, recorded the codes, and dropped it back to them.

    The code suggests that the IAP (Intake Air Pressure) Sensor is faulty.
    According to the manual, this means, replace the vacuum hose, and the IAP sensor, and the trouble goes away.

    I am guessing the IAP is a simple MAP sensor in car speak (I can understand that terminology).

    Should have the parts and bike back on Monday. If I don't, I expect you will hear of a shooting incident!