Topic: GT2871 with Synapse BOV- Issue at Idle and Low Speeds

[elff]

Just to see if I have a small vacuum leak, I hooked up the lines with both A and B ports and zip tied the crap out of them. 
Besides that dip in Rpms at a stop, I can't say that I am having any issues.  Car runs strong.  Fast as balls. Antistall valve didn't resolve it for me, but I still have some tweaking to do with the preload spring spring, so I'm not going to say it hasn't resolved anything.
It did resolve the dip at idle, just not on the street

[spicy3480]

If it fixed it at idle, then maybe a slight adjustment of the preload spring will do the trick!

[elff]

I removed the y today and did a long drive to pick up some parts.
Shouldn't have been a long drive but it took forever for me to get out of my area due to them working on every F-Ing major road.
On the way back I drove 30 minutes out of my way and saved 30 minutes in the process.
grrrrrr
Anyway, on the way Up, I got the Code Miller was talking about.
I went back to Port B only and I got the code again.
Im currently adjusted all the way out and need to tweak it some more.
It's weird, sometime when I come to a red light, I don't get that stutter, other times I do.

It's about 60/40 right now.

[spicy3480]

Hmmm.  I haven't thrown a code yet.  I have not done a WOT run yet, though.  Have you taken a log Elff? Maybe it is something in the tuning? Just throwing ideas out there.  My screw is adjusted all if the way out, using port B only, and the anti-stall is as tight as it can go without holding the piston.  Maybe try taking the BOV off and getting the anti-stall as tight as you can??

[miller11386]

Spikey,

You need to drive the car for a few hours to get the code to be thrown. It will pend for quite a while.

I think if you loosen the antistall bolt you may get this code to go away, bit I did take the time to try that yet

[spicy3480]

Gotcha...I've done a bunch of driving with nothing yet...I'll keep you posted! Can that code be turned off with HP Tuners?

[miller11386]

Im sure it could, but Id rather try to adjust around it rather than turn it off. Its associated with the k04s cbv being stuck closed from what I understand.

[spicy3480]

Good information to know.  I'll keep you posted.  So far so good on my side.  Elff...idk how far you are from me, but if you wanna meet up and work together to try and fix it, I sure will.  Maybe you have a vacuum leak? Kenny has the kit to check that. 

[elff]

I only have that stumble at the stop.
If I had a leak, I would think I would have problems elsewhere.

[elff]

I got that cbv closed code again.
I removed the AntiStall Kit.  Seems to cause more issues than it helps.

Im gonna make a Boost test kit just to be safe, but I really don't think that is the issue.

Shabby
Just curious
How would we go about relocating the Maf to the driver side IC Pipe?

[spicy3480]

Elff...it just doesn't make sense that my car has the issue solved and yours does not...do we have any differences in our setup?  What about the tune?  Lyndon modified mine from Dave.

[elff]

That anti stall made the situation worse.  I'm not sure about the tune stuff.
I'm still waiting on DDM for the HP tuners before I can start logging and swapping tunes

I am real curious about Shabby's suggestion.

Like I keep saying, except for the drop when I come to a stop, everything else is running great.  Smooth at all speeds.  Boost comes on insanely quick, shifting is fine. 

[spicy3480]

Hmmm...just doesn't make sense...mine immediately went away after the anti-stall install.  Are you sure you had it installed correctly?  Maybe you made it too tight?

[miller11386]

Im also curious ab the maf relocation

Ideally I want to get it on the cold pipe behind my Bov, however I want to hear the pros and cons from shabby, dave, etc.

[elff]

I removed the Antistall this morning.
It isn't doing anything and I keep getting the following
"P2261 - Turbo/Super Charger Bypass Valve - Mechanical"
I actually tried switching to Port A and playing with the preload spring tension.
Nothing worked.
Car runs the same without the AntiStall but without the code.
Actually, car runs ridiculously smooth via Port A.  Even better than Port B in my Case and tons better than A + B.  A+B was rough.

I have a leak tester on the way with both gauge and tire valve.  I will put money on the fact that I have no leaks.  The stumble is do to my BOV venting to atmosphere.  
So I have to figure out a way to feed it back into the intake.  

[elff]

I'm wondering if I'm having an issue with the new turbo.
With the antistall removed I am getting the P2261.
Also please remember me stating that I get a turkey gobble sound from day 1.  I thought that was the BOV and so did Synapse, but it didn't go away with the new BOV.


DTC P2261
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P2261: Turbocharger Bypass Valve Stuck Closed


System Description
The BorgWarner™ dual-scroll turbocharger (TC) incorporates a wastegate that is controlled by a pressure differential, that is determined by the engine control module (ECM) by means of a PWM solenoid, in order to regulate the pressure ratio of the compressor. A charge air bypass valve is integrated within the unit, and is also controlled by the ECM by utilizing a remotely mounted solenoid to prevent compressor surging and damage from vibrations by opening during abrupt closed throttle conditions. When the valve is commanded open during closed throttle deceleration conditions, the bypass valve allows the air to recirculate in the TC and maintain compressor speed. Within a calibrated range during the closed throttle event, or upon a wide open throttle command, the valve will then close to optimize TC response.

Front wheel drive platforms also incorporate a charge air bypass valve vacuum tank. The purpose of the tank is to provide an instant source of vacuum to the bypass valve, when it is commanded open by the ECM. This results in less pressure buildup under closed throttle conditions, thereby reducing compressor noise and surge.

The purpose of this diagnostic is to determine if the charge air bypass valve is stuck closed. The ECM will first verify the integrity of the following sensors. The ECM then compares the actual measured mass air flow (MAF) to a modeled airflow that is derived from these inputs:

• Throttle position (TP)

• Engine speed

• Intake air pressure sensor

• Manifold absolute pressure (MAP) sensor

Conditions for Running the DTC
• DTCs P0033, P0034, P0035, P0096, P0097, P0098, P0099, P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0121, P0122, P0123, P0221, P0222, P0223, P0234, P0236, P0237, P0238, P0299, P2227, P2228, or P2229, is not set.

• The boost pressure versus the BARO pressure ratio is between 1.1-3.3.

• The charge air bypass valve has been commanded ON for greater than 1 second immediately after an abrupt closed throttle has occurred and the resulting pressure ratio across the compressor exceeds the calibrated pressure ratio limit.

• The battery voltage is between 10-18 volts.

• This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC
The ECM by comparing the measured MAF to the modeled MAF has detected a series of pulsations in the induction system that exceed a calibrated threshold.

Action Taken When the DTC Sets
DTC P2261 is a Type B DTC.

Conditions for Clearing the MIL/DTC
DTC P2261 is a Type B DTC.

Reference Information
Schematic Reference
Engine Controls Schematics

Connector End View Reference
Component Connector End Views

Description and Operation

• Turbocharger System Description

• Boost Control System Description


Electrical Information Reference

• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
Control Module References for scan tool information.

Circuit/System Verification
Verify that DTC P0033, P0034, or P0035 is not set.
⇒ If any of the DTCs are set, refer to DTC P0033, P0034, or P0035.

Use the scan tool output controls to command the TC Bypass Solenoid ON and OFF. An audible click should be heard and felt.
⇒ If the click is not heard or felt, refer to DTC P0033, P0034, or P0035.

Set up the scan tool for a snapshot of the induction data list. With the emergency brake on, the vehicle transmission in neutral, and the engine idling, perform a wide open throttle and then quickly release the accelerator. Review the Boost Pressure Sensor parameter. There should not be any abnormal pulsations of the parameter.
With the parking brake ON and the engine idling in neutral, perform an audible test of the valve by depressing the throttle wide open, then quickly releasing it to a closed throttle position. A valve that is stuck shut will generate a turkey gobble sound. There should not be any unusual noise.
⇒ If there is unusual noise, refer to Turbocharger Cleaning and Inspection.

Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing

I've had that Turkey Gobble sound from the day it was installed.  Monica was laughing at it.

So my question now is,
Is there a Bypass valve on the 2871?

[Gentleman Jack]

Elff,
I don't know the answer to your question, but I do know I get that sound sometimes... Perhaps your problem is my problem too?  Keep me posted if you find anything.

[elff]

Gj
With the K04 this should indicate the bypass valve.
I have to see how this relates to a 2871?

[Gentleman Jack]

Not the same set up?  Your synapse could be malfunctioning?

[elff]

I put it back on Port B.
If it goes away, then it's not a happy camper on Port A.

I would think it would refer to the BOV because that's why I need a BOV.


DDM has another busy week, so I'll talk to Dave afterwards.
Still, the Turkey Gobble is something I'm just not sure about and seeing it in the code description really made me go
WTF?
Especially since Steve and Miller do not have that noise.

Other people besides yourself have indicated they get that noise occasionally.

[kennysabarese]

The Garrett compressor does not have a bypass valve. The bypass valve on the K04 serves the same purpose as a BOV on your setup. The K04 bypass recirculates, your BOV does not (but it can if you run a hose back to the compressor inlet, which is what the K04 does.)

But the same solenoid that opens and closes the BPV is what is opening and closing the BOV. It's on the intake manifold, where many tap for a boost gauge.

[miller11386]

You sure this gobble isnt surge? IE you let out of a low boost slowly and get a slight noise back through the turbo?

If I heard it I could tell you.... Come up to ajax in july and we can take a peak at it!

[elff]

Im 100% positive it is not surge.  That has been covered in the other thread with audio.
I was not getting the P2261 when I was running to Port B alone.  I tried both A + B as a test, and then A only as another test to see if I could eliminate the stalling.
So I am back to Port B and need to drive the car for a day or 2 to see if that eliminates the P2261.


Kenny
Do you have a pic of where the compressor inlet is?
I'd like to see what my options are for recirculating.  With this car having a MAF, I really think that is the solution.

[kennysabarese]

Look at a picture of the stock turbo. You can see where it goes. There is an L shaped thing going right to the inlet with a blak hose going to it. The hose is connected to the BPV white plastic cover.

This is all wrong. I updated on the next page

[miller11386]

elff - I would encourage you not to recirculate from the hot side. You will heat up your intake air. From what I understand thats a big no-no and under heavy load you could experience high IAT's which (in worst case) would lead to detonation.

Not sure if that's a reality or not, but its what I have been told.