Suddenly getting misfires on all four cylinders

@rjparker.... Thanks. That was up on the list of things to try, but there is another storm coming in now... I'm not sure I'll get to it for a few days. Question though.... I'm assuming that I would hear the bucking in the engine though if the root issue were EGR related, right? Or would the influence be so subtle that I'd not hear a hiccup?

 

Thank you for the link. I had actually seen that video a year ago and was aware of the scraper trick; it was on my list of things to try, especially since it seemed likely that the issue was somehow linked to EGR/PCV/etc. According to weather underground, there was an upcoming 2 hour period before rain, which gave me a good opportunity to do the test because it is pretty easy.

First, I wanted to get the motor warm and in the "shuddering" state. Going through the different times I've experienced it, the motor always was warm and had about 0.4 miles driven, so I wanted to do that and witness the shudder. Plus, I wanted to see if I felt I could hear the motor hiccup. In the end, I decided that it was damned hard to tell exactly what the motor *really* sounded like because the roads here suck. That, combined with road noise even at 30MPH makes a *concrete* opinion there kind of difficult. So, I retracted some of my previous thoughts there.

I basically drove around the neighborhood, and got the shudder. I then made the turn back home and spent 5 or 10 minutes putting the paint scraper in place. Off I went. With all the bumps and lousy roads it was bit difficult to say there was *no* shudder, but what was *very* obvious is that, at the very least, there was significantly less. And that by itself is a good sign. I then did the same zip back home and removed remove the blocked return line and took the car out again. The shudder was there (or pronouncedly worse).

So, I think it is fair to say that the EGR valve is a problem. Cool... I'll order a new one of those because I literally just cleaned this one. That has me mystified, but I don't want to beat a dead horse. It is easier to replace the thing and call it a day. I'll also have to figure out if the TSB software update referenced in the video was ever applied. I'm guessing it was as the car was serviced by a dealer until about 3 years ago.

All of this makes me wonder if the EGR was causing the misfire problems on the original engine. No, it still didn't explain the loose rockers, but maybe the misfires... I seem to have experienced two failures at once... Multiple overlaying problems and transients are always the hardest to fix whenever doing any type of engineering issue, so I seem to have inherited the perfect storm here. Still, I'm happy that it looks like we are the tail of this thing. And I'm grateful for the continued thoughts/help while working through the problem

I'll keep y'all posted.

 

Hi Greg,
Yeah, I'm trying to find the P/N for that right now. I'm not having great luck. The kit referenced in the video has a PCV valve in it.... I am assuming that is what I'm looking for, but thus far the only thing I can find is 04004-58137, but that seems to be just the valve and the gaskets.

Do you guys sell the kits? On Edit: I think it is toyota 04004-58137. I'm not sure what kit the guy got that included the PVC valve, but there was one of those in the rebuilt engine anyhow, so I'm not worried about that

 

Well I *know* I have the inverter update. How do I know that? Because my inverter died on me. Nothing like getting into your car, pushing the button and... the uneasy quiet of a completely dead car.... Fortunately, the inverter system was still under warranty so Toyota picked up the tab for that. Not so fortunately, somewhere along the way, the steering position sensor got messed up between the time the tow truck got the car, transported it 2 miles to the dealer, and my getting it back. No idea who was responsible for that, but there was an awful lot of finger pointing going on. Fortunately, the car had been at the dealer the week before and they noted in the logs that there were no error codes at all, so Toyota agreed to pay for half of the repair. In the end, my "free" inverter wasn't so free, but the at least it was fixed for not too much.

Anyhow, at that point in time, Toyota was doing a TSB for updating the inverter firmware because the old firmware was, I am told, burning up inverters.

 

I'm not sure to what you are specifically referring. If you are talking about Chapman's last comment, then yes and no. Is it *specifically* relevant to fixing the problem? No. Do I mind the discourse? No, as long as the thread does not migrate into a Toyota engineering thread. My primary goal is to get my car running perfectly again, of course, and secondarily to help others that may have similar problems find solutions without wading too much.

But, don't misunderstand me. I've been employed in engineering for my entire life from avionics, maritime robotics, NASA, and a variety of completely unrelated commercial software systems. I also have a machine shop in my garage and I'm heavily embroiled in commercial CNC machinery. So, yes, I find the comments made by Chapman to be extremely interesting as it relates to the *design* of the inverter subsystem. For what it is worth, I deal with inverters and VFDs frequently on CNC equipment. I've never designed one, but I have done a fair amount of reverse engineering, diagnosis and repair of them. So I follow Chapman's thought process. Will it directly help solve the bucking Bronco (aka, my Prius) and the presumed EGR problem? No. But it is all very interesting.

I'm a curious bloke. I *guarantee* you, for instance, that I'll be taking my old engine apart. I want to understand why the rockers become easily dislodged. And, if my inverter failed, I guarantee you that I'd be taking that apart too, although with the migration to custom ASICs, it is hard to get too much use out of those types of endeavors. When I almost thought my A/C pump went on the Fritz, I was going to take that apart too because I was curious about the VFD they are using inside that. It is in the blood. But, of course, curiosity always kills the cat!

 

Yep, that is a very valid point, @ChapmanF . I think it is worth the extra input in the hopes that it corrects perceptions on where problems may lie. FWIW, I was absolutely *not* "digging" at you. I found the comments very interesting. I try to approach all boards like PriusChat with an even keel. And, yes, I think there is huge benefit in having all of this information public facing. I know that I've learned a lot from other threads, and I hope that others may find benefit in this thread as well.