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Cylinder 2 misfire at 1500-1700rpm please help diagnose

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bikes4u, Aug 5, 2019.

  1. bikes4u

    bikes4u Member

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    Hello All---I have a gen 3 with 267k miles runs amazing until 3 days ago.

    I bought it with aprox 200k a little over a year ago and cleaned EGR and installed OCC shortly thereafter. I also marked the coolant reservoir with a sharpie at that time and the level has not moved.

    I have a misfire from cylinder number 2 at 1500-1700rpm . I have changed the coil with new, changed plug with new and swapped around the fuel injectors to see if the problem followed. Nothing changed. Today I put in a bottle of Heet fuel additive and a bottle of Lucas fuel injection cleaner and drove it for over 100 miles, nothing changed. I also cracked open the EGR pipe to check it and there is not much suet there.

    Where should I go from here? Is there any chance of a sensor or vvti causing an error in the fuel mixture for cyl 2 at 1500-1700 rpm? The car runs strong in other RPM ranges and accelerates from a stop strong.


    I have spent several hours checking wire plugs to make sure they are secure and checking for leaking, anything out of the ordinary. I have changed trans fluid and kept up on changing fluids and use synth oil.

    Thanks for the help
     
  2. schmuber

    schmuber Member

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    Stick a borescope into cyl 2 and look around.
     
  3. bikes4u

    bikes4u Member

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    Which one do you recommend? I'll only be using it 1 time.

    What other suggestions do you have while I'm waiting for this to arrive?

    Posted via the PriusChat mobile app.
     
  4. bisco

    bisco cookie crumbler

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    what model year?
     
  5. schmuber

    schmuber Member

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    It's an amazingly useful tool to have actually. I'm using mine (simple $20-ish wifi snake cam) for a lot of tasks and projects, from gunsmithing/electrical/plumbing/AC to searching for my cat's toys under the furniture. And yes, even the cheap ones do the job – just make sure that yours has at least 720p resolution, a built-in light and basic attachments (90 degree mirror, magnet and hook).

    PS: This is a screenshot from aforementioned cheap borescope that made me accept the truth about my engine… (yep, it was a coolant leak).


    head-gasket.jpg
     
  6. bikes4u

    bikes4u Member

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    2010 idk the model prob a 4...it has a sunroof and solar panel but no leather or radar cruise


    Posted via the PriusChat mobile app.
     
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  7. bikes4u

    bikes4u Member

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    Could very well be head gasket but coolant level has been same exact spot for a year now. Egr is clean as a whistle and OCC is happy

    Posted via the PriusChat mobile app.
     
  8. Triparadox

    Triparadox Active Member

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    Is there any coolant leak? The leak may be into the cylinder which is known as head gasket leak. Top off the coolant to a level easy to remember (or even mark it). Drive it for 100 miles. Check the coolant if it's going down.

    EDIT: Just noticed you said the coolant level is the same. Check for ignition coils and spark plugs. The harness for the plugs may also be the cause if it's bad.
     
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  9. bikes4u

    bikes4u Member

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    How would you recommend I troubleshoot the harness? Thanks

    Posted via the PriusChat mobile app.
     
  10. Triparadox

    Triparadox Active Member

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    Hmm.. Good question. To be honest, I don't knownit myself. I'm completely new. I've got my first car. But those are the possibilities I can think of right now.
     
  11. mjoo

    mjoo Senior Member

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    HG's can also leak between cylinders. Someone posted a few times a diagram of where HGs can fail (TheCritic?).

    Try some stronger injector/fuel system cleaner?

    Does your engine burn oil?
     
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  12. tankyuong

    tankyuong Senior Member

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    Did you clean the whole egr circuit
     
  13. bikes4u

    bikes4u Member

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    Yes it burns oil about a quart every 2k miles.

    I put 2 bottles of Lucas fuel treatment and a bottle of Heet and so far have run half a tank thru it and no change.

    If the HG is blown between cylinders I guess that means looking inside the bore wouldn't do any good because it's not burning coolant. How would you determine this?

    Posted via the PriusChat mobile app.
     
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  14. bikes4u

    bikes4u Member

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    Yes everything front to back and put on OCC. I just cracked open the egr tube and it looks good no buildup.

    Posted via the PriusChat mobile app.
     
  15. bikes4u

    bikes4u Member

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    I'm going to check compression for all cylinders.. I guess that would be the proper way of testing for blown HG between cylinders. I'll let you know what I find out

    Posted via the PriusChat mobile app.
     
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  16. mjoo

    mjoo Senior Member

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    At that mileage, It might be excess carbon sticking the rings lowering compression and increasing blow-by. A piston soak could help. Some people soak for a few days. They're good if you have time.


    Pixel XL ?
     
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  17. cnc97

    cnc97 Senior Member

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    I’m going to throw in there a burned valve. Since the coil didn’t change anything, and it’s not losing coolant, it’s either a bad injector or burnt valve. Should be easy to spot with a borescope camera or compression test. Not a common issue on the turd gen, but still possible.
     
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  18. msg4life

    msg4life Member

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    Sounds like a clogged egr cooler. Not just the egr valve
     
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  19. Pluggo

    Pluggo Senior Member

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    If the spark plug wire is cracked from heat and age it will leak voltage. Can you swap the plug wire and see if the problem follows? Also, check the other end of the wire anything obvious, such as a burnt tower.
     
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  20. Mendel Leisk

    Mendel Leisk Senior Member

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    Or leak-down test, better?

     
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