Issues with PSM and bucking/surging on acceleration
05-14-2018, 01:06 AM
#1
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Issues with PSM and bucking/surging on acceleration
I have an issue that is very frustrating and I am looking for advice from some of the experienced tuners or folks that have had the same issues modifying their .1 turbos. When accelerating from a stand still, and not launching, I will get a hard throttle cut and PSM warning lamp flashing in 1st and 2nd gear, and sometimes 3rd BEFORE the boost even comes on. The car will not accelerate past this point unless I let off the throttle or disable PSM with the button on the dash.
The answer I got from the installer is that the PSM is just not able to deal with the increased horsepower and should be switched off, but I do not believe that because the car isn't even in the powerband when this happens. The only reason I did these modifications was to cool down charge air temperatures to avoid heat soak at the track. With my stock piping and intercoolers, I was running a stage 2 COBB off the shelf map that made a lot of power for a short period of time until the IC's heat soaked and killed the HP. I always ran the track with the PSM on and never had intervention of the PSM like I do now.
I have checked for air and boost leaks and found none, there are no codes stored, checked both MAF sensor voltages (1.02v key on engine off).
I have a 2007 997.1 6MT turbo with the following mods:
bydesign intercoolers
1300cc injectors
SRM Y-pipe
SRM silicone IC pipes and inlets
SRM plenum
GT3 throttle body
COBB accessport V3 stage 3 91 octane off the shelf tune
I am anxious to get back out one the track and not have this issue hanging over the otherwise flawless operation of my turbo. Thanks for reading and I hope you all can help me out.
The answer I got from the installer is that the PSM is just not able to deal with the increased horsepower and should be switched off, but I do not believe that because the car isn't even in the powerband when this happens. The only reason I did these modifications was to cool down charge air temperatures to avoid heat soak at the track. With my stock piping and intercoolers, I was running a stage 2 COBB off the shelf map that made a lot of power for a short period of time until the IC's heat soaked and killed the HP. I always ran the track with the PSM on and never had intervention of the PSM like I do now.
I have checked for air and boost leaks and found none, there are no codes stored, checked both MAF sensor voltages (1.02v key on engine off).
I have a 2007 997.1 6MT turbo with the following mods:
bydesign intercoolers
1300cc injectors
SRM Y-pipe
SRM silicone IC pipes and inlets
SRM plenum
GT3 throttle body
COBB accessport V3 stage 3 91 octane off the shelf tune
I am anxious to get back out one the track and not have this issue hanging over the otherwise flawless operation of my turbo. Thanks for reading and I hope you all can help me out.
05-18-2018, 04:04 PM
#2
Never had issues with PSM intrusion to that level on our car, with similar mods, on a stron e85 map. Ran in normal mode, with PSM for a full track day last winter like that. One difference is we still use the standard plenum and throttle. Another could be a sensor/wiring issue after re-assembly from the mods?
05-18-2018, 04:12 PM
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With the stock piping and IC were you running the GT3 throttlebody, plenum and injectors.. Rule of thumb is to back date the latest mods "IF" your current troubleshooting has hit the brick wall.
05-19-2018, 01:50 PM
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These are all new mods done at the same time. Everything has been gone through and double checked. The engine has a flawless idle and runs fine otherwise, no codes stored and I’ve driven it hundreds of miles. If there was an air leak or an unplugged component, there would likely be dtcs stored immediately or at least after a few drive cycles. Of course there are exceptions.
I had considered the possibility of the plenum or throttle body being an issue, but the tuners I have spoken to have told me that several people run these parts without protunes and don’t have issues.
I appreciate the replies, but COBB tuning has reviewed my logs and identified AFR issues under load. They told me the car will need a protune because of the injectors I have are not built to COBB or ID specification. Off to the tuner it goes.
Thanks guys.
I had considered the possibility of the plenum or throttle body being an issue, but the tuners I have spoken to have told me that several people run these parts without protunes and don’t have issues.
I appreciate the replies, but COBB tuning has reviewed my logs and identified AFR issues under load. They told me the car will need a protune because of the injectors I have are not built to COBB or ID specification. Off to the tuner it goes.
Thanks guys.
