Zero-ing on minor engine misfire

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ktthomas, Jun 13, 2018.

  1. ktthomas

    ktthomas Junior Member

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    Hello,
    I've been trying to chase down a pesky engine misfire for a few months. Cylinder 4 will randomly misfire on start-up but then seems to run fine for the duration of my commute. It triggers the check engine light but the light will turn back off on its own after a few starts.
    I had the plugs replaced with OEM since they were due anyway. Replaced every 100k. I'm currently at 300k. I also had the coil replaced on cylinder 4. PCV valve was recently changed as well. Most recently I had the fuel injectors cleaned. None of these services had any change on the condition. And my mileage is still great (42.4 last tank) although I am burning some oil (1000mile/qt).
    My mechanic measured the resistance on all the injectors and everyone of them was out of spec with cylinder 4 being the worst. So he is leaning towards replacing the injectors. His explanation was that cylinder 4 injector may be opening slowly the 1st time but once it opens it starts functioning normally.
    Anything else I could try before dropping $700 on the hopes that this is the problem ?

    Thanks,
    Keith
     
    #1 ktthomas, Jun 13, 2018
  2. padroo

    padroo Senior Member

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    Ask your mechanic to do a fuel injector leak down test to confirm equal flow through all injectors. I will look around and see if I can find a good video of the procedure.


     
    #2 padroo, Jun 13, 2018
    Last edited: Jun 13, 2018
  3. edthefox5

    edthefox5 Senior Member

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    Personally I would start thinking about a new engine. Your already eating a lot of oil and that will only get worse.
    For $1000 you may be able to get a used lower mile motor and have it installed. No way I would invest $700
    In a 300k motor. That’s foolish.
     
    #3 edthefox5, Jun 13, 2018
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  4. padroo

    padroo Senior Member

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    #4 padroo, Jun 13, 2018
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  5. SFO

    SFO Senior Member

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    I would try another mechanic, only because I don't have $700 to spend on a "may be" for a vehicle with 300k miles.

    If you trust your mechanic and believe that your fuel injectors are "out of spec", then why not replace them with a set of rebuilts and install them yourself.

    You can get four (4) fuel injectors that have been cleaned, tested and rebuilt for under $30 including shipping and a ''lifetime warranty" (cough), and if don't need a lifetime warranty for a vehicle with 300k then you can save even more.

    On a side note, many mechanics (and other professionals) get wholesale or jobber pricing on all part(s) purchases. Example: Four new OEM/Denso injectors cost $640 and installation is $60 (one hour of labor), for a total of $700. Many parts suppliers offer a discount around 20% or more off MSRP, meaning that your mechanic could be making an additional $120 (or more) on just these new parts (which may not fix your problem, please come again).
     
    #5 SFO, Jun 14, 2018
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  6. JC91006

    JC91006 Senior Member

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    I'd second the recommendation on a new engine, don't put money on an engine with 300k miles
     
    #6 JC91006, Jun 14, 2018
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  7. ktthomas

    ktthomas Junior Member

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    Where can I get a set of injectors for $30 ? I was going to look into the priuschat injector exchange, I think a set was like $80 if that is still happening ?
    It's a little too early to junk the motor imo. It still runs good and I think it still has some life left in it and this is really the 1st major repair it's needed but I agree $700 is too much to spend.

    Keith
     
    #7 ktthomas, Jun 15, 2018
  8. padroo

    padroo Senior Member

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    Check my link above for Rock Auto for cheap fuel injectors.
     
    #8 padroo, Jun 15, 2018
  9. edthefox5

    edthefox5 Senior Member

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    swap injector position around see if the misfire moves to that cylinder. You said you had the injectors cleaned. how was that done?
     
    #9 edthefox5, Jun 15, 2018
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  10. edthefox5

    edthefox5 Senior Member

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    btw have you ever run the engine so low on oil a check engine light came on or the red triangle of death?
     
    #10 edthefox5, Jun 15, 2018
  11. SFO

    SFO Senior Member

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    4x OEM DENSO fuel injectors for Prius, Echo/Scion xA/xB 1.5L 23250-21020 | eBay

    and

    4x OEM DENSO fuel injectors for Toyota Prius/Echo, Scion xA-xB 1.5L /23250-21020 | eBay

    There are other refurbished options beyond the two $24.99 listings posted above.

    If you want to take one for the team you could buy/test a set of four (4) injectors ('New') for $30.99 which includes shipping from California : Upgrade Fuel Injectors set of 4 for 2001-2009 Toyota Prius 23250-21020 New | eBay
     
    #11 SFO, Jun 16, 2018
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