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Backfires while starting

Discussion in 'Motorcycle Tech Talk' started by hanke777, Mar 19, 2008.

  1. hanke777

    hanke777 New Member

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    I have a 2001 road king. Most of the time when I start the bike it will backfire out the exhaust or sometimes or sometimes out the Carb (EFI). If I cycle the Ignition switches and hold throttle open a little it will start most of the time. It seems to be the same hot or cold. The check engine light stays on while it's running.
  2. cowboy

    cowboy Moderator Staff Member

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    sound's like the timming is slipping some how ,you just might have to shop it so they can plug in the computer & read the list , before you do it , double check to make sure it's not sucking air around the intake
  3. chucktx

    chucktx Moderator Staff Member

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    in your service manual......the one under the rags on the upper shelf.......will give you instructions on how to pull codes and read what they mean.....that manual will save you money if you use it......i would pull the codes myself before taking it into the dealer.....at least you will know what needs to be done..........................:)
  4. hanke777

    hanke777 New Member

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    Re bakfires when starting

    I get a code 42 and a PPU 82883
  5. chucktx

    chucktx Moderator Staff Member

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    ok. i dont have a rk manual, but yours should give you what the code means...not sure where in the book it will be. maybe someone that has the manual can decifer it........................:)
  6. roadkinger

    roadkinger Member

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    In the manual i have from 1999 to 2005 code 42 comes up as camshaft position sensor.Can`t help you out with the PPU, if i find it i`ll get back to ya...:D
  7. chucktx

    chucktx Moderator Staff Member

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    that helps.....sometimes the sensor will get dirty, just as the speedo sensor does. should be able to remove it and clean it. being faulty will cause backfireing..............:)
  8. hanke777

    hanke777 New Member

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    Thanks I will give it a try and let you know how it works out.
  9. hanke777

    hanke777 New Member

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    I cleaned the cam sensor; still back fires. Could it be the throttle position sensor?; because if I hold the throttle open a little it fires up every time.
  10. roadkinger

    roadkinger Member

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    I guess you can try and clean it too.For the throttle position sensor the code is 11, if your wondering.
  11. hanke777

    hanke777 New Member

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    So if I understand this correctly the bike generates a code 42 (cam sensor error) when it backfires. And the PPU 82883 code is a historical code with the 82883 being a part number? And it will clear after 50 good starts.
    I have been thinking of moving the throttle position sensor a little either way and see if that helps; or am I opening a can of worms??

    Thanks
  12. chucktx

    chucktx Moderator Staff Member

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    has the problem always been there for you? you can try to move the positioner a little, but i am not sure it will help. you can mark it and always move it back. hopfully someone versed in efi will get ya on the right track...........:)
  13. hanke777

    hanke777 New Member

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    Thanks,
    I have had the problem for a while now, but I have been able to work around it (opening the throttle a little); once she started runs great.
  14. Jim Posey

    Jim Posey New Member

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    The ignition basics on EFI same as carburated on newer bikes, both electronic. Both Duel fire I think. EFI has several additional sensors to adjust timing and fuel mix where carburater does not, Ox sensor, throttle position, map sensor ect ect. You have on board computer where I have electronic ignition box.
    Thats why yours will run so well in high altitude, they adjust for the air density and Ox content. If the cam Sensor is getting dirty thats a problem that should not be happening. You either have a poor fitting ignition cover or a seal leak from Crank case letting oil residue into the ignition compartment. It should be spotless and bone dry in where the sensor is. Timing could have slipped. That would be odd. That sensor has 2 screws which hold it in place. When slightly loosened thats how you adjust timing by moving that sensor to advanced or retard the spark timing, Take a flash light and look at the base plate for signs of movement, cleaner area exposed on seating lip. Nothing touches that sensor so if it moved it has to be pretty loose. The back fire sounds like during start excessive fuel build up in cylinders and exhaust telling me that code is saying your sensor may be failing. That can mean intermitant spark. If you see any goowee stuff leaking from Cam sensor its on its way out of this life. It also has drop switch built into it if its like mine. Thats little balls inside that are suspended in a fluid goop. If bike falls over like during wreck it grounds out ignition to shut off bike. My FLHT 1997 was first year to incorperate this honey of an expensive feature. Harley gets 170 for new Cam sensor compared to about 40 bucks in 1996. I have found on internet old style with out fall sensor that says is compatable with late model 3 wire sensors. Web site saved on my lap top. If you want let me know and I will post. That system you have is good in that when it detects a fault such as a miss fire or sensor falure it points to the culpret. My Carburated bike needs a multi meter, shop manuel and ohm checks and volt checks on the various componets. If its intermitant, then when checked some times its missed. You end up on the side of the road some place. If its telling you Cam Sensor, I would trust it !! If you change, mark exsact position of old sensor and duplicate new one into that spot. If timing is correct it should be ok.
    Good Luck and Good Riding JP:cool:
  15. hanke777

    hanke777 New Member

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    Wow thanks for all the good food for thought. I think you right if the bike is telling me it's the Cam Sensor, I should trust it!
  16. Jim Posey

    Jim Posey New Member

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    Hope thats it Hanke777, It can be many other causes but your check engine light is most likly telling you what to go after. Some time I wished I had the EFI.
    Good Luck with it. JP

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