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Bad injector causing piston to knock?

Discussion in '2nd Gen 4Runners (1990-1995)' started by grousehunter 61, Apr 7, 2016.

  1. Apr 7, 2016 at 1:47 PM
    #1
    grousehunter 61

    grousehunter 61 [OP] New Member

    Joined:
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    Rodger
    Vehicle:
    1995 4 runner
    Anybody that has been following my other post on a knock in my motor knows that I am dragging my feet on pulling the motor. I started yesterday to remove things from the motor and today I pulled the injectors, they were a mess. The one in back passenger side, #5, was not working or I can't see how it was.

    GEDC0008%201_zpsleu8j1x0_0c7e3240125fc0907f4614791e51f159448820b4.jpg

    The rest were bad but not that bad. Could a bad injector as in not firing cause that piston to knock??

    GEDC0010%201_zpscyaiexum_10b9b6d568cc0511d0c25d58f25e181f335870b1.jpg

    I have not pulled the spark plugs yet but will do so when the outside temps cool off a little.
     
  2. Apr 8, 2016 at 6:38 AM
    #2
    RonT4R

    RonT4R New Member

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    Ron
    Virginia Beach
    Vehicle:
    2007 4runner SR5 4WD
    In my opinion........yes, if that cylinder is not firing the piston is just free sliding in the cylinder bore and without any compression from ignition could possibly cause the noise. The question now is, is there any damage to the cylinder wall or piston on that cylinder.
     
    Bob likes this.
  3. Apr 8, 2016 at 9:44 AM
    #3
    grousehunter 61

    grousehunter 61 [OP] New Member

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    Male
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    Rodger
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    1995 4 runner
    Good question Ron, I won't know until the motor is out and tore down. I have been taking loads of pictures as I tear it down, not sure I can trust my 75 year old brain to remember where all the hoses go. I know----bite the bullet and get it done......
     
  4. Apr 8, 2016 at 5:23 PM
    #4
    wnelax04sr5

    wnelax04sr5 New Member

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    Ethan
    CT
    Vehicle:
    2004 SR5 4X4 Galactic Gray
    its possible, the issue is that the wear from movement free of compression can wear out bearings, the root cause of rod knock
     
  5. Jun 3, 2016 at 4:46 AM
    #5
    1990 SR5

    1990 SR5 New Member

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    Morgan
    Vehicle:
    1990 Red 4runner
    many lights, sound system, engine swap
    I agree with Ethan, i had the same problem and noise, and found it easier for myself to do a full engine and engine harness swap rather than rebuild mine, however mine was a blown head gasket and a warped head along with the rod knock...
     
  6. Jun 3, 2016 at 5:20 AM
    #6
    grousehunter 61

    grousehunter 61 [OP] New Member

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    Male
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    Rodger
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    1995 4 runner
    I am finally back among the living. Seven weeks after my knee replacement I am able to walk without some type of support but not able to work on the Toy. I will give it a couple more weeks before I dig back into it. With the time off, I have decided that a complete rebuild is the best route to take. I don't know this vehicle and have no idea how it was driven or taken care of. I would rather get it done all at once as opposed to haveing it break down on the road.
     
    ThatFenwickGuyFromTW and RonT4R like this.

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