- Member ID
- #17023
- Messages
- 2
- Likes
- 3
Hey everyone. I have been chasing an unresponsive boost condition in my S280 Fiesta for going on six months now, and am reaching out to the community for insight. I've taken the car to multiple shops a dozen times, spoken to multiple tuners, taken the car to a reputable tuner, I've contacted multiple vendors and no one seems to be able to get this resolved. Tonight I put everyone whom I've spoken to or paid to look at the car into one email to try and see if shared feedback can't get us some solutions. Now I'm reaching out here, as we're all at a loss.
In the past year and six months I have purchased tens of thousands of dollars in parts, tunes, or labor attempting to get this project working. However, this car has now stumped multiple people, multiple ASE Certified professional shops, and both of my tuners. Absolutely no one seems to be able to find any specific reason as to why this vehicle cannot build boost pressure despite the replacement of virtually every boost control related part, up to and including newly purchased parts, and despite the motor and turbo seemingly working as designed. I have put us all in one place hoping to change that, and in the hopes maybe together we can pull off a diagnostic Christmas miracle and at long last get my car working correctly.
I am not here to blame or point fingers at anyone, and I'd ask that all of you maintain that spirit as well. I am strictly here for technical insights. I want to see if we can find a resolution with our combined knowledge, because I'm completely exhausted with fruitlessly chasing this problem as I'm sure my shops and tuners are as well. This is the most expensive thing I've ever done outside of paying my mortgage, and it has been an obsession to build a car like this since I was a kid, I still completely adore this car, and I am still absolutely sure there is a way to make it work, I just don't know what is missing. So perhaps working together we can find some answers.
Full background and approximate timeline;
-July 2024, I spun a rod bearing at an autocross event at Atlanta Motor Speedway necessitating the replacement of the long block in the car.
-August 2024, After talking to my local shop and inspecting the rod bearing damage myself, we decide to replace the engine in the car.
-September 2024, New OEM long block ordered, deposit paid waiting for shipping.
-November/Dec 2024, While the motor was being replaced I ordered an S280 turbo kit, and 14psi TurboSmart wastegate to put on the car, along with a Spongebob clutch all purchased from Whoosh.
-Jan 2025, The motor arrives and is prepped for install, the shop is gracious enough to let me pay it off in a few installments over the course of a few months.The turbo, clutch, and wastegate are installed at this time. I buy an S280 tune from Dizzy. (A 500 Abarth I stupidly purchased to drive while the Fiesta was being worked on required thousands in repairs on delivery and complicated the repair progress on the Fiesta.)
-April/May 2025, The motor and turbo are in the car, it's put on an S280 basemap with Dizzy and initial datalogs are pulled. Jason sends me maps back to load into the car and the boost pressure does not change as expected, Jason suspects a boost leak as a potential cause as well as potential misrouting of the vacuum lines on the boost control solenoid.
-June 2025, Car is tested for boost leaks and none are found. I find two mis-routed lines on the boost control solenoid, correct them with the owner of my local shop, pull more datalogs, receive more maps and load them into the car and still no change with the boost pressure. (14psi) I stop by GMP and ask what in their experience contributes to a problem like this and they mention the wastegate could be a suspect.
-July 2025, I contact TurboSmart regarding the pre-load on the wastegate and the installing shop owner and I put it in the air check the pre-load noting it might be off, and put a couple turns on the actuator rod, and I after speaking to Turbosmart I switch to monitoring the WGA duty cycle in the Accessport to verify that it's working and I can see the duty cycle apparently working. With the adjustments at the rod the car makes 18psi, but again does not respond to any tunes.
-August 2025, I contact Brian at JST Performance and purchase a pro-tune to aid in diagnosis and to try and rule out any tuning related issues as a cause. I perform datalogs on his basemap, load the new maps and the same issues persist.
-September 2025, I inspect and replace the blow off valve thinking maybe it's stuck open.
-November 2025, I drop the car off with the installing shop owner again to check the wastegate preload again, and with adjustments he is able to get it up to 20psi with a few more turns at the road, but again nothing when commanded by the tune or when maps are changed. I also contact Ron at Whoosh looking for answers.
-December 2025, I contact Brian at JST again, and drive down to Dublin to drop the car off with him for diagnosis and hopefully a dyno tune if it can be resolved. He suggests the boost control solenoid may be the culprit and its replaced, again no change in behavior or response to tuning. He suspects a bad wastegate, notes that it is leaking a small amount of psi every 30 seconds. I contact Ron regarding the wastegate and order a new one. We replace it, it holds boost correctly without leaking when pressurized but the issue persists. The actuator rod works as it should. Brian finds two small boost leaks, and corrects them. No changes. He tests the electrical output at the BCS harness based on a video the installing shop has sent and it seems to be working correctly. I call TurboSmart and speak to two different employees about the issue both of whom seem stumped based on the circumstances involved. But as of this afternoon has told me he is also out of ideas.
We have now confirmed that all the routing on the boost control solenoid is correct, we have confirmed the pre-load on the wastegate twice, we have replaced the boost control solenoid, we have leak tested the car multiple times, I have replaced the wastegate, we have replaced the vacuum lines on the boost control solenoid, we have put the car back on an original base map, I have tried different tunes and different maps, I have replaced the BOV and personally watched the Accessport command changes to the wastegate duty cycle in the Accessport, and we seem to have a nominal voltages coming from the harness to the BCS, and the BCS triggers a code when unplugged suggesting the circuit is operational. On the new wastegate the car is once again only making 14psi, and not responding to tunes. The turbo has been tested with the wastegate capped and makes 27psi when it is run in that condition, and I can hear it audibly spooling when I've been driving it around and can feel it coming on at whatever the wastegate spring pressure is set to. Fundamentally it seems as though the BCS is not getting any kind of reference to increase pressure to meet targets specified by the tunes, and no one can figure out why.
Car is a 2019 Fiesta ST with the following engine modifications;
Woosh Short Ram Intake
Whoosh Crossover Pipe
Whoosh V3 Front Mount Intercooler
Whoosh Catted Downpipe
Thermal R&D 3' Exhaust
Turbosmart 14psi Wastegate x2
Turbosmart Kompact Shortie BOV x2
Turbo Technics S280 Turbo
Whoosh Performance Coilpacks
Whoosh Symposer Delete
NGK Iridium (1 Step Colder, Pre-Gapped)
Cobb Accessport
Cobb Rear Motor Mount
Does anyone have any ideas or suggestions as to what else might be contributing to this problem?
Would anyone be willing to share any insights or similar problems they've seen or how they were resolved?
Does the BCS get a reference from anywhere other than the turbo outlet, and is it measuring that data based on differential pressure or is it strictly seeing outlet pressure, and then opening and closing the solenoid to control vacuum to the wastegate based on targets set by the ECU?
Is the turbo packaged with anything that might have become stuck in an small orifice and not immediately obvious to the naked eye that might obstruct or prevent flow to the BCS?
If the MAP sensor is compromised could it provide bad reference data to the BCS without throwing a check engine light?
Brian at JST Performance currently has the car in for diagnosis and I was hoping dyno tuning, and he is now just as stumped as the rest of us have been these last few months in trying to resolve it. Any help at this point would be enormously appreciated. It has been a year and a half, and nearing fifteen thousand dollars all in between the various parties at this point, and I have reached the point where I'm about to give up hope this can be resolved.
If anyone here has any suggestions as to where to look, what might be overlooked, what specific references the BCS is pulling from that could be compromised I am all ears. No one, has been able to figure this thing out. I've been modifying cars for 20 years, and have spent five in a separate but similar field diagnosing different kinds of vehicles professionally, and I now work with pneumatic and electrical systems daily. My local shop is run by a master ASE certified tech who's built turbo Miatas, neither he, nor Dizzy, JST, or Whoosh seem to be able to figure it out, and technical support at TurboSmart couldn't seem to understand how it still wasn't working given the things we've tried. I am admittedly relatively new to the world of turbocharging but I've owned this car for five years now, and feel like I understand the basics well enough that it shouldn't be this complicated to diagnose.
I am at a complete loss. And I'm completely exhausted, and this is starting to make me question if I don't want to get out of this hobby that has brought me so much joy over the years altogether. Please try to avoid speaking ill of any of the parties involved, I frankly don't care about assigning blame to anyone who may have made a mistake, I am simply looking for a solution because at this point none of the enormously talented people I've worked with on this project have been able to figure it out either and sometimes that's just how this stuff goes. I absolutely cherish this little car, and I just want to get it working again.
Cheers.
In the past year and six months I have purchased tens of thousands of dollars in parts, tunes, or labor attempting to get this project working. However, this car has now stumped multiple people, multiple ASE Certified professional shops, and both of my tuners. Absolutely no one seems to be able to find any specific reason as to why this vehicle cannot build boost pressure despite the replacement of virtually every boost control related part, up to and including newly purchased parts, and despite the motor and turbo seemingly working as designed. I have put us all in one place hoping to change that, and in the hopes maybe together we can pull off a diagnostic Christmas miracle and at long last get my car working correctly.
I am not here to blame or point fingers at anyone, and I'd ask that all of you maintain that spirit as well. I am strictly here for technical insights. I want to see if we can find a resolution with our combined knowledge, because I'm completely exhausted with fruitlessly chasing this problem as I'm sure my shops and tuners are as well. This is the most expensive thing I've ever done outside of paying my mortgage, and it has been an obsession to build a car like this since I was a kid, I still completely adore this car, and I am still absolutely sure there is a way to make it work, I just don't know what is missing. So perhaps working together we can find some answers.
Full background and approximate timeline;
-July 2024, I spun a rod bearing at an autocross event at Atlanta Motor Speedway necessitating the replacement of the long block in the car.
-August 2024, After talking to my local shop and inspecting the rod bearing damage myself, we decide to replace the engine in the car.
-September 2024, New OEM long block ordered, deposit paid waiting for shipping.
-November/Dec 2024, While the motor was being replaced I ordered an S280 turbo kit, and 14psi TurboSmart wastegate to put on the car, along with a Spongebob clutch all purchased from Whoosh.
-Jan 2025, The motor arrives and is prepped for install, the shop is gracious enough to let me pay it off in a few installments over the course of a few months.The turbo, clutch, and wastegate are installed at this time. I buy an S280 tune from Dizzy. (A 500 Abarth I stupidly purchased to drive while the Fiesta was being worked on required thousands in repairs on delivery and complicated the repair progress on the Fiesta.)
-April/May 2025, The motor and turbo are in the car, it's put on an S280 basemap with Dizzy and initial datalogs are pulled. Jason sends me maps back to load into the car and the boost pressure does not change as expected, Jason suspects a boost leak as a potential cause as well as potential misrouting of the vacuum lines on the boost control solenoid.
-June 2025, Car is tested for boost leaks and none are found. I find two mis-routed lines on the boost control solenoid, correct them with the owner of my local shop, pull more datalogs, receive more maps and load them into the car and still no change with the boost pressure. (14psi) I stop by GMP and ask what in their experience contributes to a problem like this and they mention the wastegate could be a suspect.
-July 2025, I contact TurboSmart regarding the pre-load on the wastegate and the installing shop owner and I put it in the air check the pre-load noting it might be off, and put a couple turns on the actuator rod, and I after speaking to Turbosmart I switch to monitoring the WGA duty cycle in the Accessport to verify that it's working and I can see the duty cycle apparently working. With the adjustments at the rod the car makes 18psi, but again does not respond to any tunes.
-August 2025, I contact Brian at JST Performance and purchase a pro-tune to aid in diagnosis and to try and rule out any tuning related issues as a cause. I perform datalogs on his basemap, load the new maps and the same issues persist.
-September 2025, I inspect and replace the blow off valve thinking maybe it's stuck open.
-November 2025, I drop the car off with the installing shop owner again to check the wastegate preload again, and with adjustments he is able to get it up to 20psi with a few more turns at the road, but again nothing when commanded by the tune or when maps are changed. I also contact Ron at Whoosh looking for answers.
-December 2025, I contact Brian at JST again, and drive down to Dublin to drop the car off with him for diagnosis and hopefully a dyno tune if it can be resolved. He suggests the boost control solenoid may be the culprit and its replaced, again no change in behavior or response to tuning. He suspects a bad wastegate, notes that it is leaking a small amount of psi every 30 seconds. I contact Ron regarding the wastegate and order a new one. We replace it, it holds boost correctly without leaking when pressurized but the issue persists. The actuator rod works as it should. Brian finds two small boost leaks, and corrects them. No changes. He tests the electrical output at the BCS harness based on a video the installing shop has sent and it seems to be working correctly. I call TurboSmart and speak to two different employees about the issue both of whom seem stumped based on the circumstances involved. But as of this afternoon has told me he is also out of ideas.
We have now confirmed that all the routing on the boost control solenoid is correct, we have confirmed the pre-load on the wastegate twice, we have replaced the boost control solenoid, we have leak tested the car multiple times, I have replaced the wastegate, we have replaced the vacuum lines on the boost control solenoid, we have put the car back on an original base map, I have tried different tunes and different maps, I have replaced the BOV and personally watched the Accessport command changes to the wastegate duty cycle in the Accessport, and we seem to have a nominal voltages coming from the harness to the BCS, and the BCS triggers a code when unplugged suggesting the circuit is operational. On the new wastegate the car is once again only making 14psi, and not responding to tunes. The turbo has been tested with the wastegate capped and makes 27psi when it is run in that condition, and I can hear it audibly spooling when I've been driving it around and can feel it coming on at whatever the wastegate spring pressure is set to. Fundamentally it seems as though the BCS is not getting any kind of reference to increase pressure to meet targets specified by the tunes, and no one can figure out why.
Car is a 2019 Fiesta ST with the following engine modifications;
Woosh Short Ram Intake
Whoosh Crossover Pipe
Whoosh V3 Front Mount Intercooler
Whoosh Catted Downpipe
Thermal R&D 3' Exhaust
Turbosmart 14psi Wastegate x2
Turbosmart Kompact Shortie BOV x2
Turbo Technics S280 Turbo
Whoosh Performance Coilpacks
Whoosh Symposer Delete
NGK Iridium (1 Step Colder, Pre-Gapped)
Cobb Accessport
Cobb Rear Motor Mount
Does anyone have any ideas or suggestions as to what else might be contributing to this problem?
Would anyone be willing to share any insights or similar problems they've seen or how they were resolved?
Does the BCS get a reference from anywhere other than the turbo outlet, and is it measuring that data based on differential pressure or is it strictly seeing outlet pressure, and then opening and closing the solenoid to control vacuum to the wastegate based on targets set by the ECU?
Is the turbo packaged with anything that might have become stuck in an small orifice and not immediately obvious to the naked eye that might obstruct or prevent flow to the BCS?
If the MAP sensor is compromised could it provide bad reference data to the BCS without throwing a check engine light?
Brian at JST Performance currently has the car in for diagnosis and I was hoping dyno tuning, and he is now just as stumped as the rest of us have been these last few months in trying to resolve it. Any help at this point would be enormously appreciated. It has been a year and a half, and nearing fifteen thousand dollars all in between the various parties at this point, and I have reached the point where I'm about to give up hope this can be resolved.
If anyone here has any suggestions as to where to look, what might be overlooked, what specific references the BCS is pulling from that could be compromised I am all ears. No one, has been able to figure this thing out. I've been modifying cars for 20 years, and have spent five in a separate but similar field diagnosing different kinds of vehicles professionally, and I now work with pneumatic and electrical systems daily. My local shop is run by a master ASE certified tech who's built turbo Miatas, neither he, nor Dizzy, JST, or Whoosh seem to be able to figure it out, and technical support at TurboSmart couldn't seem to understand how it still wasn't working given the things we've tried. I am admittedly relatively new to the world of turbocharging but I've owned this car for five years now, and feel like I understand the basics well enough that it shouldn't be this complicated to diagnose.
I am at a complete loss. And I'm completely exhausted, and this is starting to make me question if I don't want to get out of this hobby that has brought me so much joy over the years altogether. Please try to avoid speaking ill of any of the parties involved, I frankly don't care about assigning blame to anyone who may have made a mistake, I am simply looking for a solution because at this point none of the enormously talented people I've worked with on this project have been able to figure it out either and sometimes that's just how this stuff goes. I absolutely cherish this little car, and I just want to get it working again.
Cheers.
Last edited:
