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2001, Engine Vibration (missing badly), Flashing CEL

Discussion in 'Generation 1 Prius Discussion' started by DaveGoodrich, Sep 26, 2019.

  1. ronlewis

    ronlewis Active Member

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    Gosh, I've never heard of there even being an EGR on these cars, but I'm only a few months into them. On the other hand, EGR issues are a big problem on my Ford diesel trucks. My SnapOn app lists these possible causes for a 304 in the order in which they've been searched(?) or whatever on the app:

    Spark plug
    Coil
    MAF
    injector
    catalytic converter
    spark plug wire
    ECU
    oxygen sensor
    cold starting fuel pump
    fuel pump and fuel senders

    FYI, that app has a lot of generic info, so I'm not sure which of these apply, but it seems indicative that EGR is not even listed.
     
  2. ronlewis

    ronlewis Active Member

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    I think you're going to find that it's either the plug, coil or injector.
     
  3. ronlewis

    ronlewis Active Member

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    Oh, wait, the EGR valve. Yes, I've heard that can be a problem. I've not had to mess with one yet. Those are a big problem on my trucks, but not the valve so much as the big EGR cooler. That's what I was thinking of - actually about to tear into my truck to replace that and an oil cooler, so I had that on my brain.
     
  4. ronlewis

    ronlewis Active Member

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    Yeah, swap those plugs, coils, injectors first. It's just so easy there's no reason not to try it.
     
  5. ronlewis

    ronlewis Active Member

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    Hopefully, your reader can clear codes, so you don't have to wait for them to reset from driving.
     
  6. DaveGoodrich

    DaveGoodrich Member

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    Looks like there is no egr on the Gen 1. Someone please correct me if I'm wrong.
     
  7. DaveGoodrich

    DaveGoodrich Member

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    Updates: swapping coil packs between cyls 1 and 4 didn't change anything. Still code 0304 after resetting. Plugs look ok, brown deposits.

    I'm now worried that it's not an engine issue at all. Now, after the troubleshooting described above, it is acting weirder. When I first start it, it runs ok, then within 15 or 20 seconds, it starts shaking and rattling badly, and the ABS light came on.
    What makes me think it's not the engine, is that, when the vibration/rattling starts, the car seems to want to lurch forward a bit, even though it's in park. That's bad, right? PSD?
     
  8. ronlewis

    ronlewis Active Member

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    I don't know what that lurching is, but I've had mine do it. They will also rock sideways/front back.
     
  9. ronlewis

    ronlewis Active Member

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    Of course, it could be that several of your coils/injectors are bad such that swapping around doesn't change anything. At first you had multiple cylinder misfires. Wish I could be more help.
     
  10. DaveGoodrich

    DaveGoodrich Member

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    Because this car lives at the metro station, far from my home, it is difficult to find time to troubleshoot. So I have decided to go ahead and replace all the plugs and ignition coils, just to eliminate those as a possibility. Parts are ordered, but won't be here until after the weekend. Something changed after swapping the #1 and #4 coils, because it started shaking much worse. Perhaps it is now missing badly on two cylinders, instead of just one.

    If the ignition parts aren't the problem, the next step will be the injectors. What is involved in getting to those?

    Thanks,
     
  11. ronlewis

    ronlewis Active Member

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    They're simple to pull. So you never moved them around? I thought you would do those while you did the coils. They're just as likely to be bad as the coils. probably, IMHO, more likely than the plugs.

    When you have the air cleaner off, they're right there under the fuel rail. The one of the right, #4, is a tight squeeze, but it can be done.
     
  12. DaveGoodrich

    DaveGoodrich Member

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    Nope, because the car isn't at home, I'm having to do this diagnosis a few minutes at a time on my way to/from work. I will (hopefully) eliminate ignition issues tomorrow (either eliminate the problem, or eliminate the ignition as the cause of the problem) by replacing all the coils and plugs. No, that's probably not the cheapest way to go about it, but its the way that lets me move the troubleshooting along more quickly, and with fewer trips back and forth to the car. The coils have several hundred thousand miles on them, so I don't feel to bad about the money spent, and the plugs are cheap, so I don't mind replacing them either while I'm at it.

    This car is by far, the cheapest car, per operated mile, that I have ever owned. If I have to spend a few hundred dollars either fixing it, or making sure it is really beyond hope, I am fine with that.

    Thanks for your help and suggestions.
     
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  13. ronlewis

    ronlewis Active Member

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    I like that rationale. I had no problem buying routine maintenance parts for mine either. They're going to need to be replaced anyway. In your case, you've gotten your money out of this car long ago and any such investments are like buying a pittance for a nice used car. Keep going, you'll figure it out.
     
  14. DaveGoodrich

    DaveGoodrich Member

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    I replaced all 4 coils and plugs this morning, and so far, so good. It ran well on the way into the office this morning. That may not mean anything since it was an intermittent problem. It is definitely much better than when I left it on monday, and I think I know why. When I replaced the #4 plug today, I found the rubber "thingy" from the inside of the spark plug wrench still on the old plug that I reinstalled on Monday. I think it was preventing the coil on that cylinder from contacting the plug. So that cylinder probably wasn't firing at all, and making the shaking and rattling much worse than it had been.

    So its either "all good" now, or I am just back to the intermittent state I was before Monday. I'll update this thread either way when I find out.
     
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  15. Q*bertZ

    Q*bertZ Member

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    I have seven Prius'. The one with 311,000 miles on it needed a new fuel pump. Which means the whole gas tank needed to be replaced. Now runs fine. Did you make sure you are getting fuel pressure? One of my others started having p0300,p0301, and p0302. random, cylinder 1 and cylinder 2 missfires. I had already changed the plugs and coils. that did not fix the problem. I checked the fuel pressure and it was 50 psi. I then took out my fuel injectors and cleaned them, put them back in and problem is solved.
     
  16. ronlewis

    ronlewis Active Member

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    My long lost brother! What'd you do with Mom?
     
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  17. DaveGoodrich

    DaveGoodrich Member

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    Well, the coils and plugs didn't fix it. It started missing on the way back to the station from work on Friday. I hadn't been back to the car until this morning. I pulled the codes, and it is showing P300, P303 and P304 codes.

    My next step was going to be replacing all the fuel injectors. Before I do that, How do you check the fuel pressure?
     
  18. ronlewis

    ronlewis Active Member

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    I think there are threads here discussing the solution. IIRC, it's a PITA to test and a bigger PITA to fix (swap the entire gas tank). I got a set of good injectors off Ebay for $40.
     
  19. DaveGoodrich

    DaveGoodrich Member

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    Anybody know of a good set of instructions or youtube video explaining how to replace the injectors? Thanks,
     
  20. ronlewis

    ronlewis Active Member

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    Real simple. Remove air filter. A few easy bolts to lift the fuel rail up. It doesn't want to get out of the way on the driver's side but you can still get to that injector by forcing it out of the way just a little. Swap all in less than 30 mins.