I NEED Boost... Opinions puh-lease

[yaris2010RS]

Originally Posted by Focus_Sh1ft

No, all four plugs are getting fouled. Even though the afrs are running from super rich to super lean, they're generally on the rich side (especially in open loop). There's no way all four injectors are suddenly sticking. I'd also expect to see a slightly higher compression in one cylinder from carbon buildup.

Also, to be clear, when I run open loop my afr sensor is NOT plugged into the harness and NOT downstream. Therefore no values are being read.

Even though the ecm is ruled out, I still can't get over the nagging feeling that this is somehow electrical (I checked all fuses BTW)...

$130 is alot for a sensor i have a spare one kicking around in my garage LOL, Should have asked man....

Im sorry to try to stick on one thing, but it sounds ALOT like what my car was doing when the ECM was gone......

Have you done a compression test? good place to loose vac is in the cylinders is a leak test on the intake passed. if this was a vac leak on the hose or cracked intake mani i believe you would get a very unpridctible idle (up and down or really high) with the car running spreay some brake cleaner or WD40 or something flamable and controlable to see if your RPMS go up when you spray suspected spots.

Another shot in the dark (im good at these but that doesnt make them useful) have you checked the condition of your turbo? possibly if its in dire need of a rebuild it could be holding up enough back pressure to screw with things. check from intake and exhaust side. also while your at it check the rest of your exhaust system or some sort of blockage (if you have a cat, check it!)

These are all the things i checked on my car. they went the cause but i had convinced myself they could be

[Focus_Sh1ft]

Spent the last few hours combing over the car with my mechanic... and nothing.

-Fuel pressure was fine
-Smoke test turned up nothing
-All sensors are within range via OBDII

We were finally able to get a P0171 code thrown, but that's it. The trims were everywhere - off gas they were trimming fuel like crazy, while on gas it was adding way too much fuel. In other words, they've never seen anything like this before.

So at this point, the only thing that can't be ruled out 100% is the ECM. However, the replacement ECM didn't do anything. The one and only remaining cause is a problem with the harness. Here's what I'm thinking

-Sweet talk someone at Toyota into doing some monitoring with the techstream tool. If the ECM is compromised or a short/open in the harness, it should show up.
-If not, attempt to continuity check EVERY SINGLE WIRE on the ECM (dear lord). I don't even know if the information for this is actually readily available.
-If not, attempt to source a replacement harness

Otherwise... We're talking complete engine replacement. I knew the day would come, but I thought it would be because I BLEW the engine, not some electrical BS.

[CTScott]

Originally Posted by Focus_Sh1ft

Spent the last few hours combing over the car with my mechanic... and nothing.

-Fuel pressure was fine
-Smoke test turned up nothing
-All sensors are within range via OBDII

We were finally able to get a P0171 code thrown, but that's it. The trims were everywhere - off gas they were trimming fuel like crazy, while on gas it was adding way too much fuel. In other words, they've never seen anything like this before.

So at this point, the only thing that can't be ruled out 100% is the ECM. However, the replacement ECM didn't do anything. The one and only remaining cause is a problem with the harness. Here's what I'm thinking

-Sweet talk someone at Toyota into doing some monitoring with the techstream tool. If the ECM is compromised or a short/open in the harness, it should show up.
-If not, attempt to continuity check EVERY SINGLE WIRE on the ECM (dear lord). I don't even know if the information for this is actually readily available.
-If not, attempt to source a replacement harness

Otherwise... We're talking complete engine replacement. I knew the day would come, but I thought it would be because I BLEW the engine, not some electrical BS.

I have a Techstream. Take a run up to CT.

[Focus_Sh1ft]

I wish I could Scott, but with how the car is running it's not feasible. Thanks for the offer tough.

I was thinking though... If I shipped you one of these ECMs I have, could you possibly confirm if it's in a working state? Obviously doing the check through my car and thus the harness would be best but... Yeah. Still, if I could find out if the ECM is good or bad, that's still a pretty good datapoint.

One other thing regarding checking the harness... In the service manual's ECM pinout, would I be right in thinking the two pins listed under 'Symbols (Terminal No.)' should always have continuity?

[CTScott]

Originally Posted by Focus_Sh1ft

I wish I could Scott, but with how the car is running it's not feasible. Thanks for the offer tough.

I was thinking though... If I shipped you one of these ECMs I have, could you possibly confirm if it's in a working state? Obviously doing the check through my car and thus the harness would be best but... Yeah. Still, if I could find out if the ECM is good or bad, that's still a pretty good datapoint.

One other thing regarding checking the harness... In the service manual's ECM pinout, would I be right in thinking the two pins listed under 'Symbols (Terminal No.)' should always have continuity?

I can definitely check out the ECM for you. I can also give you a list of specific harness points to check (the ones most likely related to the behavior).

[Focus_Sh1ft]

Originally Posted by CTScott

I can definitely check out the ECM for you. I can also give you a list of specific harness points to check (the ones most likely related to the behavior).

I would definitely appreciate the harness points list. I'll get back to you on the ECM though. I need to see how the dealership responds to my request first. Considering we've bought three cars from them, I hope reasonably...

[CTScott]

Originally Posted by Focus_Sh1ft

I would definitely appreciate the harness points list. I'll get back to you on the ECM though. I need to see how the dealership responds to my request first. Considering we've bought three cars from them, I hope reasonably...

Here it is:

Yaris ECM - Connections.pdf

[Focus_Sh1ft]

Wow, that is comprehensive. Must have taken awhile to put together too. Thanks!

[CTScott]

Originally Posted by Focus_Sh1ft

Wow, that is comprehensive. Must have taken awhile to put together too. Thanks!

Fortunately I had most of it together from some past projects. Start with checking out the wires related to the injectors, coils, cam, crank, and MAF. If those all check out, then the next stop would be the AFR and O2 sensors.

[Focus_Sh1ft]

Been away for the last two weeks, but got back into troubleshooting yesterday. It looks like I've [unfortunately] found the problem...

Short story: Blew the head gasket

Long story: Finally decided to bite the bullet and get Toyota involved. I was lucky enough to get a really cool tech who was interested in the car. First thing we did was hook up the techstream tool. Get this - there were five codes that were being thrown EVEN THOUGH THE CHECK ENGINE LIGHT WAS OFF. Only his Mongoose cable was able to retrieve them. That is the biggest load of bull. Anyway, had P0300, 0301, 0302, 0303, and 0172. Since the plugs are ruled out, he said it's possible (especially with a hotter plug) that the coils burnt out. It seems unlikely all four would go, but apparently it's happened before.

So after running the engine a bit, we removed all four plugs. Out of cylinder one (and only one) you could hear air escaping/vacuum. That was the first nail in the coffin. After that, we topped off the coolant and ran a coolant reservoir with the engine on. Sure enough, there were air bubbles and small pieces of aluminum...

I still don't fully understand how a head gasket leak would cause issues such as misfires, but the guy working with me was very knowledgeable. My coolant temperatures were never excessively hot, and there isn't any coolant leaking out of the head either.

So, that's it. There's a lot I need to figure out, but I refuse to return the car to stock.

[Bluevitz-rs]

through in a new head gasket and maybe turn the boost down a bit. Or try and find a stronger one? I guess it depends on where the leak is when you get it apart. You'll probably find a tiny slit of black on the deck where the leak was. I've experienced this exact head gasket problem on a B18 LS Vtec on my friends old race car. Car kept overheating though, no other issues.

[cali yaris]

Get that tC out and park the Yaris?

[Focus_Sh1ft]

Originally Posted by cali yaris

Get that tC out and park the Yaris?

I wish it was that simple. Of course this had to happen mid winter...

I plan on upgrading the head gasket if there is a better one available. I'll probably begin tearing down the engine tomorrow, but going to do another compression test first (did the other one wrong apparently).

Can anyone chime in on the best way to deal with the timing chain?

[yaris2010RS]

PULL! lol
What do you mean "Deal" with it?

[Focus_Sh1ft]

Pretty good progress today. I'm almost there, but am kind of stuck on the camshafts / timing chain.








So yeah... those camshafts. I've looked at the service manual and not only does it not make sense, but I can't get the plug out of the "service hole." Further, the flange nut on the number two camshaft sprocket isn't budging. My wrench is actually stripping it. It looks like I may be able to just remove the retainers and wiggle the camshaft out with the gear still on, but I dunno. Can anyone give me some pointers?

[Bluevitz-rs]

You'll have to take the front of the motor apart. Probably need to release the auto tensioner and lock it back then pull the chain off the crank and then off the cams.

[yaris2010RS]

man..... after work ill try to take some pics for you of my torn down engine to try and help explain....

you'll have to remove the timing cover. once its off, remove the tensioner (by removing the preload then unbolting it). Once the tensioner is removed you can slip out all the chain guides and there should be enough play to pull the chain off the crank sprocket.

Once the chain is off the crank sprocet you should be able to pull the chain off the cam sprockets without removing the sprockets from the cams

EDIT: LOL, almost the exact same thing bluevitz-rs said....

[Focus_Sh1ft]

Thanks guys

...I was really trying to avoid taking the chain cover off