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Which engine would you pick JDM gen 3 or used or gen 4?

Discussion in 'Gen 3 Prius Technical Discussion' started by daley, Mar 24, 2024.

  1. rjparker

    rjparker Tu Humilde Sirviente

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    It does actually run the engine longer than 10-15 seconds? Many think the engine is running but it’s just the electric motor spinning it at 1000 rpm.

    Measure the 12v with a meter while in Ready mode. Should be 13-15vdc. It does not need the engine for this, just needs Ready mode. If not there look for that issue.
     
  2. rjparker

    rjparker Tu Humilde Sirviente

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    I would not use an aftermarket Amazon egr valve if that is what you have. Same goes for maf or map.

    Amazon egr known to stick open
    IMG_4720.jpeg

    Gen3 JDM engine won’t run
    Misfire codes
    @SaneAutoYoutube
    @Georgina Rudkus
    @Tombukt2
    @ChapmanF
    @Mendel Leisk
     
    #22 rjparker, Apr 10, 2024
    Last edited: Apr 10, 2024
  3. daley

    daley Junior Member

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    I am using the EGR that came off my previously working engine, it is an OEM original.

    I really think there is something preventing it sparking or injecting fuel, or somehow the timing is out.
    I will check all the fuses in the morning. I will also swap out the throttle body I have for a known working one.
     
  4. ASRDogman

    ASRDogman Senior Member

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    You should spray some carb cleaner or starter fluid in the intake when it's
    trying to start, take the air filter out. If it starts, you know it's not getting fuel.

    If it was running with the other engine, then something is probably not connected.
    It's easy to miss something. Like a vacuum hose?
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Easy hose to miss is the PCV to intake manifold connection; it needs to be connected after the intake manifold is dropped in, and out of sight is out of mind.
     
  6. Danno5060

    Danno5060 Active Member

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    A bad O2 sensor wire also caused my Gen 3 to run rough and have trouble starting.
     
  7. daley

    daley Junior Member

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    Ok so I played around with it today. Engine is running but severe shaking/knocking still happening.

    I put new plugs, swapped o2 sensor, checked all hoses/connections, charged battery, disconnected battery for an hour.

    It will start and run and heat up and shows no codes now, however there is a severe shaking/knocking coming from the transmission side of the engine.
    If I put it in drive and have my foot on the brake the knocking goes away and becomes more of a wobble feeling. Car will move forward and back and no check engine lights are on.

    The engine itself sounds good but the knocking/shaking, I need to fix.

    Could this be a problem with the transmission flex plate? I used the one that came on the JDM engine.

    Am I right in thinking if this was computer related I would see some codes?
    Thanks for all your advice and support everyone, It is very much appreciated
     
  8. rjparker

    rjparker Tu Humilde Sirviente

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  9. C-in-DC

    C-in-DC Member

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    if it’s a gen4 Jdm engine I thought the clutch plate needed to be replaced with the gen 3 plate? They’re different sizes.
     
  10. daley

    daley Junior Member

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    I got it going!!!

    Two of the connectors to injectors had bad wires, they looked ok but following the repair manuals diagnostics led to testing the pins out and they failed so soldered new connectors on for now to test and it fired right up, will de pin and do properly now I know it runs!
     
  11. rjparker

    rjparker Tu Humilde Sirviente

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    Looks can be deceiving and it looks like you caught her in the act and straightened her out prior to divorce.

    Its always something simple in the end. Next time don’t pull so hard on the wires when disconnecting.
     
  12. analoggirl

    analoggirl Member

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    True story, my 16 year old son really really really wants a Prius☺️.
     
    #32 analoggirl, Sep 5, 2024
    Last edited: Sep 5, 2024
    Tom(ง︡'-'︠)ง likes this.
  13. analoggirl

    analoggirl Member

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    so I have also been looking at the option of putting engine for engine in my Jen three. What I'm reading says it can be done, but you're mentioning there's an issue with swapping. Can you tell me about that? Thanks
     
  14. Tombukt2

    Tombukt2 Senior Member

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    Yes you can read all about it here The gen4 engine is the same as the Gen 3 they've changed some piston rings added some skirting few small things like that and are calling it done I guess because this engine is now gone gen 3 and 4 they moved on to the 2AL or two something which is a 2 l so there's always that seems to me that's the mod I would be trying to do but the generation 3 would never be worthy of that I'd have to find one and like brand new condition and I'm not looking The Gen 4 you wind up with a couple hose reroutings things like that nothing really super major and that's about it and it should run and work as a few people here who've done it there's a few hose connection hullabaloos but they're not anything that's that serious usually when you're doing something like this you have something to drive You always want to make sure you have something to drive and a way to work so you don't have to make faulty silly decisions in a hurry because you need to get somewhere if that makes sense that way there you can work calmly easily and get things done correctly It is a big help that's why I have three or four vehicles and a couple of bikes and all of that around here because we don't want to get in a big huffing puff over not being able to get down to the store or whatever it might be but yes you can easily put the Gen 4 engine into the Gen 3 car Is that the end-all be all I wouldn't think so but oh well it's the last thing you'll probably do to the generation 3 to be honest about it let's be clear.