"New" Gen 3 prius with busted HG

I am second guessing my thought to replace the water pump without diagnosing the one from the "new" engine. If it is actually operating fine, along with the thermostat then I will have spent $200 to replace parts that still work. The impeller spun freely when I tried it by hand, and I have heard about getting a 12V source and testing Batt+ to Ground to see if it goes. I will not get a chance to work on anything until next week by the way.

 

Also, unless anyone wants to come and get my spent engine or have me mail them parts I will be taking it to the scrap yard in a week. So far I have taken off:

Water pump
A/F sensor

EGR and intake are both off, and will be cleaned when I get the time.

 

Time for an update. I learned more about these water pumps, and found that the impeller from the older engine spun more smoothly. I put that impeller in the body of the pump from the new engine, Put that on the engine and replaced the thermostat (I did test the old one in boiling water and it seemed OK still, and used compressed air to force coolant backwards from the thermostat housing, which perhaps cleared some blockage or something. That issue seemed to be resolved.

I just took it on a 400mi round trip journey, and it pretty much went totally fine. I did have the tires rebalanced to address some vibrations only above 70mph.

There is one issue that I have noticed which suddenly got worse. Every once in a while I would notice that the engine would struggle and shake when accelerating. It would only last for about 1 or 2 sec. It would sometimes happen during warmup, but just as often it would happen later in the cycle. I have also had the codes P0441 and P0455 which keep coming back, indicating something with the fuel supply. Yes, the gas cap is on tight, though I have not tried swapping it. I DID have old gas in it, though now I have gone through about one tank of new gas with an injection cleaner mixed in. I was hoping that the old gas was the issue. So I just kept clearing the codes.

With about 5mi left in my trip I started to notice a slight loss of power, like the tires were grabbing the road and then coasting. This was happening very fast, and I thought I may have been imagining it. 3mi from home I was noticing the same shaking that I mentioned in the previous paragraph, but all the time. By the time I got home it was shaking pretty badly. I now have those same codes, as well as a misfire for Cylinder #3. Any ideas? I have done some searches on the forum and will do more. I cannot find any hoses unhooked, or anything unplugged or loose.

I was wondering if it may be a filler neck issue. I looked in the hole just now and I do NOT see the metal flap that I am used to seeing. Does the prius not have it?

 

I swapped some stuff around to see if there were misfires on different cylinders. First I swapped plugs and coils for Cyl 3 & 4. I did notice a little bit of oil on the tip of plug #3, but not of #4. I used techstream and saw that now there were misfires in both cylinders. I then swapped plugs and coils for Cyl 1 & 3. So now

Cyl1=Original stuff from Cyl4
Cyl2=No swap
Cyl3=Original stuff from Cyl1
Cyl4=Original stuff from Cyl3

I then got a lot of misfires on Cyl4

Then I thought "OK, maybe injectors?"

Swapped those around
Cyl1=Injector #3
Cyl2=Injector #4
Cyl3=Injector #1
Cyl4=Injector #2

Now misfires on Cyl2 and Cyl4 (mostly still 4).

Given these results I think I would rule out plugs, coils, and injectors. Could it be the pump?

I tested the Evap valve mounted on the intake with 12V and it seems to have no issue. Also, when engine running it is closed (finger could feel no pressure on end of valve that goes to vapor canister).

I really feel at a loss at this point. Perhaps the misfire is not actually related to the evap system leak. Upon learning more about this system it seems that the only misfire stuff it would perhaps cause would be from the valve on the intake staying open and let extra vapor through, which would result in a rich condition. I swapped the gascap with my 2012 Tacoma just to see, and no change in misfires.

Right now it seems that I have registered misfires in Cyl3 (original code), a lot in Cyl4 right now, and some also in Cyl2. Could it be a fuel delivery issue? How would I even check that without taking it to a shop? Besides, wouldn't the computer register a lean condition and throw a code for that?

I could run it more and play around with deciphering fuel trim data, but it is really shaking a lot and I am not too keen to run it for any period of time.

 

I actually did not check that in techstream first, though I did get a code for Cyl3. I was thinking that the plug and coil from Cyl3 were not the issue since there were misfires on both 3 & 4. I could be wrong though.

 

So I got access to the fuel pump this morning. By the way, one of the reasons I am suspicious about it is because when I took the rail off there was nowhere near as much fuel that came out as when I did it a month ago. That was the case today when I disconnected the line in the engine bay, about 1.5-2oz came out. I pulled out the pump and took it apart, putting the top part back on the hole in the tank so I do not have an open gasoline take hanging out in my garage for a couple of days . I took some pictures of the little pump and it's filter.

It looks pretty clogged to me?? As I understand it the next thing would be to test I would check that the resistance is less than 3Ω and more than 0.2Ω. My multimeter is under a tarp outside in the rain, but I will get it when the rain lets up. I have no way of knowing if this part has ever been replaced, but like the thermostat I am inclined to change it out anyway since it can't hurt and might help. Any thoughts on this plan? I have heard of people just changing the component pictured and not the whole pump assembly, does anyone have the part number I would need for that?

Edit: I have tested the resistance and it is 0Ω. I used 12V to run it and it spins right up no problem. So maybe it is OK and is not my problem after all? Is there a way to replace just the filter?

Here are some pics of various parts of the repair process.

First, I figured I would take a shot of the Cat while I had easy access. It looks fine, though looks can be deceiving.


Next up we have the hybrid battery fan prior to cleaning. Gross!


Say goodbye to the old engine!


These are inside Cyl1 in new engine. I took these after first rough patch a week ago fearing a steam cleaned cylinder. It seems OK to me though.

 

Well, the new fuel pump got here and I tested it for pressure. 0psi. Huh, I could hear it running... I then made sure all my fittings were tight, and lo and behold, the shraeder valve that I spliced into the line was not fully seated. AKA, no pressure. I fixed that and got above 40psi, I can't remember the exact number. Ok, fire it up! BANG BANG BANG! Still misfires. Not sure which cylinders, I did not check that part. So, not the fuel pump, in fact I wonder if the old one was actually fine but the test failed due to user error. It it possible that the misfires this time were due to air getting out if the fuel line, since the whole set of lines got emptied out when I unhooked the pump.

I thought to do a compression test, but my Oreilly's tester is not the right thread size. Great! Still, I decided to scope it while the plugs were out. #1 looked dry, but # 2 and 3 looked wetter, and #4 had a small ring of liquid around the compression rings. So this makes me thing that oil may have been the cause of the problem?

I took the intake off and looked under the throttle body. about a teaspoon of clean looking oil, not the usual milkshake look. Remember, I put in a catch can, and the tube from that allows air through (I checked) but did not really seem to have any residue. Ok, so not from PCV system. The only other place for oil to get into the intake (I think) would be from the cylinders themselves, right? It would be really nice to have a compression tester that fit...

So now I am thinking, try a piston head soak with Berryman's b12 chemtool to see if that helps? Controversial product I know, I could also use seafoam for a head soak.

I am still toying with the idea of clogged injectors, but I did run a tank of gas through with 16oz of seafoam in it to clear the injectors. Anyway, I removed them and will look to clean them out and test them individually. The spay ends seem clear, but the stems were super gunky.

 

I started a piston soak with seafoam yesterday, and will be turning the engine 5 times and adding more liquid every 12 hrs or so. I also bought a compression tester with the right size adapter and will use that soon. Reading more through the forum led me to take a closer look at the new spark plugs I put in this engine. It seemed like a good way to start fresh, but it sounds like counterfeit plugs have become a big issue.

They came in a toyota box, with all the appropriate markings The only two differences was that the ring had EN on them instead of the DM off the plugs from the JDM, and the end of each plug from the JDM has 3 white dots on the end of the porcelain side. Now that I am suspicious I am noticing that the "DENSO" on the new plugs is a slightly different font. I used feeler gauges to find the gaps, and the old ones measure between 1.04-1.015mm. The new ones are basically 1.02mm except for the one that was in cylinder 3 when this problem occurred. 1.09mm! that seems wrong. Also, the new plugs seemed to have a burr on the end of the ground electrode that made it hard to get the feeler gauges in. I also do not see a clear iridium pad on there. I am convincing my self that they are not the real deal.

Here is my next order of things to try:
1. Finish piston head soak
2. Compression test, if all good then continue
3. Reassemble and put in "new" plugs, perhaps with big gap in Cyl #1 since I had not found any misfires there. This would tell me that the problem may very well be the plugs.
4. Put in old plugs

Hopefully this does the trick!

 

I determined that the spark plugs were counterfeit, and once I put the original plugs in there seemed to be no issue! I should have dug into the plugs more deeply in the beginning, but ultimately am glad that I am only out $15 for the fuel pump and $40 for the plugs, and that I took my time with diagnosis instead of parts swapping. The oil in the cylinders still is a little perplexing. I did not end up doing a compression test because I did not have fitting that was small enough to thread into the plug holes.

I have been driving without major issue other than the EVAP codes. Yesterday I took a second look at the purge valve in the engine bay, and though I bench tested it and it seemed fine, for some reason it was not opening during operation. I ordered another. Also, because of the different sized evap lines from the US versus Japanese engines I had used a hose clamp to attach the bigger evap line. It seems that there is some air leakage around that, so I will wrap the valve step with electrical tape when I get the replacement. That should hopefully account for the purge flow code and the large leak code. Neither code seems to have been present when I had the old engine installed, so that points to some swapping of lines etc being the issue when I changed the engines. I believe that the purge valve came with the Japanese engine, (newer was my thought) and I no longer have the old US one.

Today I noticed some very interesting behavior. As I mentioned earlier, I have a water pump where the body is from Japan and the impeller is from the US. It has been working fine. Today WHILE DRIVING I cleared the EVAP codes and the misfire code, which I had been waiting to go away on its own. About 2mi later I see the light again, and then the dreaded "check hybrid system" lights up. I pull over into parking lot and see that the temp is about two 230ºF. I read the code and it said P261D. I had never seen that on any threads, just P261B and C. I restarted the car and it still said "check hybrid system", so I cleared it and stepped on the gas to see if the water pump worked. Once the engine started it quickly dropped the temp down to its normal operation. What the heck is going on here? I drove it home without issue, keeping an eye on the temp and it never went above 192ºF.

When I got home I hooked up techstream and did the electric water pump test and it seemed to operate fine, warming the lower hose and matching the requested rpm from the ECM.

Has anyone ever had an issue like this? As far as I can figure the ECM/pump freaked out when I cleared the system of the EVAP and misfire codes and decided to take the day off until I reset the codes again.

 

I kindof wonder about the air out of the system question. I have run it for several hundred miles and the coolant reservoir is full, I am not sure what else to do to bleed the air out. I Guess that I could park on a slant for a while, but it is parked nose up in my driveway and nose down at work.

For now I think that I will resume normal operation, but only clear codes when car is not moving, and keep an eye on the temp.