BOV venting early, any suggestions/ideas?

[Spartarus]

Originally Posted by Sportsguy83

As far as I know, the stock ECU does not do Speed Density, so Ecutek does a workaround for it, and it uses the MAF as a temperature reader as input into the VE calculation. So yes, the MAF is still used, just not as a MAF

You are correct.

To OP, this doesn't sound like a BOV issue.

I'd like to see pictures of the vacuum lines before I can help. I have a few theories.

[tofurun]

Originally Posted by Sportsguy83

As far as I know, the stock ECU does not do Speed Density, so Ecutek does a workaround for it, and it uses the MAF as a temperature reader as input into the VE calculation. So yes, the MAF is still used, just not as a MAF

I see what it's doing now and understand that. If he wanted too though, could he cut the two iat wires on the maf harness and plug them into an iat sensor welded on the the cold side of the front mount piping? If the Ecu calculates there it should calculate the same way in an iat sensor . That set up is just saving you from needing a custom bung weld correct?

[Sportsguy83]

Originally Posted by tofurun

I see what it's doing now and understand that. If he wanted too though, could he cut the two iat wires on the maf harness and plug them into an iat sensor welded on the the cold side of the front mount piping? If the Ecu calculates there it should calculate the same way in an iat sensor . That set up is just saving you from needing a custom bung weld correct?

Definitely (although it enters into other variables for example the iat sensor calibration, window and resolution would need to match the MAF additionally you want the IAT reading as close to the cylinders as possible to minimize temperature fluctuations between the reading and the cylinder), but it's also handy to keep the MAF for hybrid tunes. MAF for drivability and SD for high volume boost.

[tofurun]

Originally Posted by Sportsguy83

Definitely (although it enters into other variables for example the iat sensor calibration, window and resolution would need to match the MAF additionally you want the IAT reading as close to the cylinders as possible to minimize temperature fluctuations between the reading and the cylinder), but it's also handy to keep the MAF for hybrid tunes. MAF for drivability and SD for high volume boost.

That's why I'm surprised y'all are running those iats from the maf block. Those temps are going to be stupid high and off compared to what's entering the engine

[Sportsguy83]

Originally Posted by tofurun

That's why I'm surprised y'all are running those iats from the maf block. Those temps are going to be stupid high and off compared to what's entering the engine

From what I've seen on different turbo setups, as long as the sensor is in that last run close to the throttle, the tune comes out pretty consistent and accurate.

[Amputechture]

Originally Posted by tofurun

Just changed an external tial waste gate on a 15 Sti. There was just that orange diaphragm that seal it. If that gets damage it will leak. Also check ur gasket on the bov . If that has a leak it'll sound like blowing air under a loose piece of tape. As long as the tune is set for speed density then there should be no reason for the maf to be hooked up. Backwards vacuum lines can cause extremely high boost and the springs in your waste gate are the only thing saving u from over boosting and going boom.

I'm curious as to what you mean by "backwards" vacuum hoses?

[tofurun]

Originally Posted by Sportsguy83

From what I've seen on different turbo setups, as long as the sensor is in that last run close to the throttle, the tune comes out pretty consistent and accurate.

Never mind..... Idk why I was thinking the maf was on the intake housing. They just put the maf on the cold pipe anyways.... Well I think I'm good now lol

[Amputechture]

Originally Posted by Spartarus

You are correct.

To OP, this doesn't sound like a BOV issue.

I'd like to see pictures of the vacuum lines before I can help. I have a few theories.

Awesome man, thank you so much. Once I am off of the clock I'm going to go snap some pictures eta 30 minutes.

[Spartarus]

It was the evap solenoid line. /solved

To any mods, this photo needs to be a sticky in the forced induction section.
@ichitaka05

It isn't obvious, many FI install directions don't cover it. Many shops and tuners, even today, still miss it.

I have seen a great many of these.

[ichitaka05]

Originally Posted by Spartarus

It was the evap solenoid line. /solved

To any mods, this photo needs to be a sticky in the forced induction section.
@ichitaka05

It isn't obvious, many FI install directions don't cover it. Many shops and tuners, even today, still miss it.

I have seen a great many of these.

Great... but I would recommend doing a write up with detail info in new thread. I can't just sticky this post.

[Spartarus]

Originally Posted by ichitaka05

Great... but I would recommend doing a write up with detail info in new thread. I can't just sticky this post.

Done.

[Amputechture]

Out of town for work so I haven't had a chance to clamp these mf'ers down or even check if they have popped off but Spartarus explained my symptoms and to a T. I will working on these this evening, and will report back. This would also explain my irregularly low IAM as my MAP sensor is reading lower than the pressure being discharged by the snail. I am praying that this is what is happening as it's a super easy fix, and I would be very surprised if it were not. Thanks again Sparty!!!!

[Amputechture]

Update: The EVAP hoses were blown off. I took the throttle body off and secured them all. Took her out for a spin and it still vents. My vac hose routing has been confirmed correct by several individuals at this point. Notified my tuner that I'm running a Crawford AOS...tuner says they are garbage for boosted applications/JDL recommends that I cap off the intake plenum and let the PCV valve VTA. It still occurs but it lets boost hold about twice as long. Again I don't have a boost gauge so I can't tell exactly what PSI it is at but if I lay into the throttle around 3K it vents off at around 5.5K. Was advised to reflash to get rid of the learned fuel trims and whatnot. Waiting until I am off of Mr. Mom duty and will reflash and see what happens.

[Amputechture]

So it looks like I'm out of the woods. It's raining cats and dogs out so I couldn't get on it too hard but after reflashing it pulls just fine up to around 5.6-5.8 K and sounds MUCH quieter than before. No early venting or strange noises and outside of some dead pedal from a new ROM it feels very responsive. Hopefully it will be dry in the morning and I can put it through some paces and log things. Thanks everyone for their input, I was very close to taking it to a shop and certainly would've gotten bent over in the process.