I NEED Boost... Opinions puh-lease

[fnkngrv]

wonder wtf if the issue at this point

[Focus_Sh1ft]

Did you ever get a chance to have someone connect up a techstream?

Yes, at the dealership. All we got were P0300-0303 and P0172 (none of which were showing up on my code readers...). Everything else appeared to be working okay with the ECM.

Things are definitely beyond desperate at this point. Let's just say I never thought I'd bring any car I ever owned to a dealership.

I've come up with a few other things to check, but at this point it's just taking shots in the dark...

[Bluevitz-rs]

Did you pull the pistons out and check for broken rings or ring lands. Could be causing blow by at the much higher pressure of expanding brining fuel than just a compression test.

[Focus_Sh1ft]

I didn't... But on all four cylinders? I'll listen to any possibility at this point though. Is there any way to test for that without physical inspection?

[Bluevitz-rs]

Idk

[fnkngrv]

I didn't... But on all four cylinders? I'll listen to any possibility at this point though. Is there any way to test for that without physical inspection?



most likely not unfortunately... :frown:

[CTScott]

Yes, at the dealership. All we got were P0300-0303 and P0172 (none of which were showing up on my code readers...). Everything else appeared to be working okay with the ECM.

Things are definitely beyond desperate at this point. Let's just say I never thought I'd bring any car I ever owned to a dealership.

I've come up with a few other things to check, but at this point it's just taking shots in the dark...

Did they watch the techstream data, with the engine running, to see if any of the sensor data seemed to be out of whack?

BlownXA mentioned the ring land issue in another thread. That does unfortunately seem like a possible cause.

I wonder if pulling the fuel injector and coil connectors, individually off each cylinder, would allow you to see if one cylinder is acting differently than the others.

[Golddeenoh]

^ yep, pull one of the ways for a cylinder to run and if your rps only drops slightly then that is the problematic cylinder. if they drop a few hundred then it is most likely not that cylinder. you will be looking for minimal change in operation.

[pimp my yaris]

My friends supra had multiple cyl. missfires. Turned out to be bad coils. He replaced them all. May be worth a shot. Also if you buy a set of Noid lights you can check the signal coming from the injectors. Its just a light bulb that attaches to the injector connector. With the starter cranking you can watch them blink.

[Focus_Sh1ft]

Guys... It's finally over. :biggrin:

It turns out it was the blow off valve!

I had just gotten a set of new coils, threw them in, and no dice. For whatever reason, the engine was running (slightly) better, and I noticed it was holding a fairly constant -12 vacuum. I don't know what possessed me to do so, but I started kinking portions of the vacuum lines. As soon as I kinked the line going to the reference port on the BOV, the engine immediately responded!

In retrospect, it's obvious why this didn't turn up in any of the four leak tests done. They all used positive pressure (smoke, air compressor), and the BOV was leaking only under vacuum (which makes sense considering how it operates).

I can't even begin to explain how relieved I feel lol...

And I'll finally be able to enjoy my new wheels I got literally the day after the problems started lol. The company I bought this (likely knock off) BOV from will definitely be hearing from me.

[Bluevitz-rs]

Can you return the coils?

Glad you finally figured it out!

[fnkngrv]

Tial BOV is the way to go for sure. If/when my HKS dies or if I get a wild hair I am gonna change to a Tial.

Awsum to hear that you finally figured it out!

[yaris2010RS]

WTF NO F'N WAY! I SWEAR IF THIS WAS MY ISSUE IMMA B PISSED.......

[Focus_Sh1ft]

^ Lol. Your compression says otherwise though. :thumbdown:

I've taken it apart and can't really figure out what's going on. My guess, since it was leaking past the valve, is that it wasn't sealing properly under normal operation. Kinking the reference line must have made it operate in reverse and force the valve closed. Maybe the spring is worn? I'm going to try shimming it before completely replacing it since I can use the Zage bov in the meanwhile.

Still can't believe the hell I've been through for something so simple. I'm especially bitter about bovs now because I also had trouble with the one in my tc lol :rolleyes:

[fnkngrv]

Dude, now you have an idea of what I went through....after I had installed my "new" engine along with the new setup for boost control I was sooooo leery and scared especially after the first few drives the boost wasn't stopping on building. That made me really frustrated and then of coursing finding out my new wastgate was missing a line plug which then buttoned it up nice and solid.

[pimp my yaris]

Glad your back on the road. And that sucks. I have had mine cause some problems but not that bad. Now I recirculate the air back to the intake. It works much better if your using the stock mass air sensor.

[Blown_xa]

^ Lol. Your compression says otherwise though. :thumbdown:

I've taken it apart and can't really figure out what's going on. My guess, since it was leaking past the valve, is that it wasn't sealing properly under normal operation. Kinking the reference line must have made it operate in reverse and force the valve closed. Maybe the spring is worn? I'm going to try shimming it before completely replacing it since I can use the Zage bov in the meanwhile.

Still can't believe the hell I've been through for something so simple. I'm especially bitter about bovs now because I also had trouble with the one in my tc lol :rolleyes:

Just needs a stronger spring. Tial ones you can select spring , Greddy can be adjusted , TurboXS you shim. Some BOV's are used for supercharged applications and require it to be open at idle ( to bypass excess air driven by supercharger). In a draw through MAF sensor application if the BOV is cracked open, the car will run like poop because of unmetered air entering the engine .