Still Misfiring After Cleaning IM - Please read

Hey there everyone, my name is Cole. I own a 2006 Prius as a daily driver and I do some fixing and selling over other Priuses on the side, usually with dead hybrid batteries. I recently took apart a prius that I am working on, a 2010, because of a 1 and 2 cylinder misfire, causing severe shaking, always at low speeds/rpm levels. When it misfires otherwise, it happens at low speeds or idle. As soon as the injectors start squirting more fuel into the engine, she clears up. Upon putting the car back together, the car definitely runs better more often, but when the misfiring occurs, it is just as bad as before I cleaned the IM. Let me tell you everything was FILTHY and has since been cleaned thoroughly with pipe cleaners as well as a bunch of carb cleaner.

This is my misfire checklist thus far as well as what I have left to do.

Spark plugs replaced 30k ago
Ignition Coils replaced
Injectors and seals replaced
Injector seating holes cleaned
Intake Manifold Cleaned (Tube diameterAbout the size of a BB before cleaning)
EGR Pipe cleaned (Very clogged)

Left to do (according to forums)
Replace PCV valve
Replace EGR Valve
Clean throttle body (Didn't look dirty upon inspection)
Replace Spark Plugs again? (They were replaced before I bought the car)

I used this video below for reference. In the comment section, someone mentioned this: "glad you finally did this video but I think you missed an important part of the manifold that needs to be checked. inside each runner there is a small port on the bottom. when I removed mine to clean it, 3 of them were completely blocked up with carbon build up. it was actually causing a cylinder misfire. I used pipe cleaners to get all the way in there."

- I then saw a few people mention that this fixed their issue as well. I thought I cleaned the intake properly, but apparently there are these little ports. Can anyone be more specific on these or maybe post a picture so I can see what he's talking about?

If I'm forgetting anything, please let me know. It's getting closer to Christmas and I would love to sell this 2010. Would be a lot of presents.

 

Thank you very much for the speedy response. So it's way deep in the port is what you are saying? I can't really see anything but i can assume its down there.

 

Thank you. I actually got a deal on the EGR valve and the cooler. I appreciate your reaching out in such good time. Thank you.

 

Sure. I'll be doing it this week. It's been actually raining here for once, keeping me inside.

 

It leaks no oil or coolant, I don't think it's a head gasket, and the way it runs well most of the time makes me think that it isn't a bent valve.

 

Funny you mention this...on my way home today from a friend's house the 2010 had a temperature flashing light that came on. It went off after a minute. I'm currently waiting on the car to cool down to add some more coolant, but this is the first time it has happened since I cleaned all the stuff I wrote about above. I think (am seriously hoping) that the coolant has finally just recirculated since I didn't add any since I started it up again. I lost a bit of coolant while pulling everything off doing the intake. I've also heard that the a bad intake manifold gasket can also contribute to this. We'll see when I drive it tomorrow. As soon as my EGR assembly gets here I will replace it.

Next question, is it really true that its easier to engine swap than it is change the gasket? I'm trying to save as much money on this repair as possible because I want to be able to flip it and make a clean 3 grand.

 

I was also changing the injectors whilst completing this job. Maybe I removed them by accident anyway. I was following a video and the guy removed the lines.

 

Just went out and filled the coolant tank to the brim. I'm pretty sure it's not a headgasket (I will compression test anyway to be sure before I clean everything I said I would) because I checked the oil and it was perfectly fine, and maybe 3/4 of a quart low which is where I saw it was last time. I also added oil. I remember one of the coolant lines didn't fit as snugly as the others. I'm gonna check that line in the morning and if its coming from there I know its that. I'm almost entirely positive it isn't the head gasket. Stay tuned....can always use the help.

 

I see what you mean. I drove it today and checked the coolant and it seems to be right where I left it, so I'm not too concerned about it.