S280 Turbo on New Long Block - Unable to Build Boost via Tune for Six Months

[Grsemky]

New TIP and MAP sensors installed today. No change. We have confirmed the harness is good, and can see the pulsed ground coming from the ECU at the BCS harness. Contacted Cobb to see if maybe there was any chance the Acessport was bad. I'm going to have a third BCS put it in because there's always the possibility the new one we bought at JST was bad.

I have another hypothesis. I get the "Hill Start Not Available" Message from time to time suggesting an ABS sensor might be bad. I'm pretty sure these sensors feed the traction control system data. Is there any possibility that is impacting torque tables in the ECU?

That's an easy feature to turn off in the sync menu, might be worth a try to turn off that feature and an even long press esc to remove stability control for the test 🤷🏼‍♂️

 

[DrivenMind]

That's an easy feature to turn off in the sync menu, might be worth a try to turn off that feature and an even long press esc to remove stability control for the test 🤷🏼‍♂️

I'll try it tomorrow. I may attempt to unmarry the AP from the car, and reupload the config afterwards. This is absurd, and I'm about ready to sell the car.

 

[Grsemky]

I'll try it tomorrow. I may attempt to unmarry the AP from the car, and reupload the config afterwards. This is absurd, and I'm about ready to sell the car.

Don't give up, there's a solution somewhere we're definitely rooting for you!

 

[sczamun]

New TIP and MAP sensors installed today. No change. We have confirmed the harness is good, and can see the pulsed ground coming from the ECU at the BCS harness. Contacted Cobb to see if maybe there was any chance the Acessport was bad. I'm going to have a third BCS put it in because there's always the possibility the new one we bought at JST was bad.

I have another hypothesis. I get the "Hill Start Not Available" Message from time to time suggesting an ABS sensor might be bad. I'm pretty sure these sensors feed the traction control system data. Is there any possibility that is impacting torque tables in the ECU?

This is the path I would go next and I would verify the ABS sensors are doing what they are supposed to be doing with an oscilloscope. I would probably do a quick check to see that the AP displays the correct gear that you're currently in.

I would hold off on replacing the BCS or at least test it manually.

 

[DrivenMind]

We found it this afternoon. Though I'm not sure I understand what the solution is going to be yet, or why it worked on the stock set up, but not the new one. I had been wondering if the BCS was seeing differential pressure, and mentioned it to the installing shop owner when I dropped it off. Per the instructions with the BCS it looks like it was routed correctly. Today my mechanic got under the car and drew a map of the pressure of everything in the lines. The turbo outlet was at 15 psi on one side of the BCS and the BCS intake return was routed to the block that the Turbosmart Kompact shortie bov is mounted to (the same one the factory diverter valve mounts to) because it was also seeing 15psi. As soon as it was removed the pressure differential was restored, and the BCS started controlling boost. With that being said, I'm now wondering where the intake return line is supposed to go, and if this bov is actually compatible with this set up. I don't think the S280 came with any charge pipes with nipples to attach to, but I presume the intake return needs to go back to the intake side before it enters the turbo. Could someone share a picture of how theirs is routed so I can compare. I also assume I need to put a plug or vacuum cap on the nipple if its not in use?

 

[atlantaM3]

def let us know how this sorts out - especially as I have an S280 sitting in the garage, so interested...

 

[DrivenMind]

I think I see whats going on here. Is it just me, or is my diverter valve mounting block in the plumbing in the opposite orientation to this set up? I think they installed it backwards. The valve in the bov is pointing towards the compressor and not the pressurized air coming out of the turbo.

 

[Grsemky]

It does look like the blow off exit is pointed towards the compressor outlet, instead of towards the turbo inlet 🧐🧐

 

[DrivenMind]

That has to be the problem then. My mechanic was telling me to run the intake return to the bov to atmosphere, but I noticed I still didn't have any bov on the test drive so I was racking my brain trying to figure out what in the world could be different about the set up. That's the problem. I can't believe we all missed it this long.

 

[Grsemky]

I always tell people to follow the K.I.S.S. method, it won't let you down