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misfiring / hesitation on accel

Discussion in 'Gen 2 Prius Main Forum' started by trip, Nov 21, 2021.

  1. trip

    trip Junior Member

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    Hello Folks,
    I have a 2008 Prius with 246K on it. Driving it in NC, but spent most of it life in the cold of Chicago.
    The check engine light does come on intermittently and many times shuts off after an oil change. It was on before yesterday and is still on.
    Yesterday I thought I would get it ready for the winter so I got an oil change, bought 4 plugs and an air filter.
    I'm not a mechanic and I don't attempt anything over my head. So I changed the plugs and filter myself. Everything went fine and no issues with anything as far as I could tell. It started up fine and drove fine during a 20 mile test drive and even seemed to get a couple of extra mpg's. However when I really accelerate, the engine misfires badly. I double checked the filter and made the sure the boots were on securely. No burning smell or anything like that. The only thing I can think it might be is I didn't have a torque wrench so tightened the plugs by feel.
    I'll probably take it in tomorrow, but wanted to post in case I missed something.
    Thanks as always. Tom
     
    #1 trip, Nov 21, 2021
  2. bisco

    bisco cookie crumbler

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    where did you get the plugs? there are a lot of fakes out there.

    have you ever had the trouble codes read?
     
    #2 bisco, Nov 21, 2021
    Moresnow and trip like this.
  3. trip

    trip Junior Member

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    I got them from Autozone at the store. I just ordered 4 new ignition coils as well. Things are a bit brittle under the hood as it's a 2008. Not only does it get cold in Chicago, it also can get pretty hot and humid in the summer. The last time I had the codes looked at it was brake pump assembly. I'll get the codes looked at if these coils don't work.
     
    #3 trip, Nov 21, 2021
    bisco likes this.
  4. ChapmanF

    ChapmanF Senior Member

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    Misfiring just under heavy load could be a dodgy fuel pump too.
     
    #4 ChapmanF, Nov 21, 2021
  5. Tombukt2

    Tombukt2 Senior Member

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    On 1nz that's a good one. Are ya sure it's not hesatating on transition from elec to gas? Like the ZZ engined way over EGR'D system ? NC gets very hot and can fall down into teens way more UV in SE USA fo sho. And I've no dry rot. Everything u derhood is original even hoses n other rubber . Outside car . That has been driven by ding bats for many years . This the lowest maintenance vehicle I've ever seen I own aircraft boats 34 vehicles that use tires in my life . Nothing can touch the GenII nothing . Gen3 not even close. The genII could be C130D over bagdad dropped n driven I guarantee it. Can't borrow a c130 anymo..

    SM-A715F ?
     
    #5 Tombukt2, Nov 22, 2021
  6. trip

    trip Junior Member

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    So I changed the coils, but also noticed that the connection to the mass airflow sensor wasn't quite all the way in.
    My guess would be that it was that connection and not the coils, but at 246K it probably wasn't a bad thing to change. Anyway, all is well in PriusLand and I'm ready to go another 246K! Thanks for the responses.
     
    #6 trip, Nov 23, 2021
    kenoarto and bisco like this.
  7. bisco

    bisco cookie crumbler

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    congrats, all the best!(y)
     
    #7 bisco, Nov 23, 2021
  8. trip

    trip Junior Member

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    right back atcha Bisco.
     
    #8 trip, Nov 23, 2021
    bisco likes this.
  9. edthefox5

    edthefox5 Senior Member

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    The check engine light coming on is because the engine oil is so low it has zero engine pressure. Very bad for this engine. Lost many a motor on this site from that.
     
    #9 edthefox5, Nov 25, 2021
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