What trouble codes are being tripped when it breaks up over 10psi of boost around 4500rpm?
Sometimes a failing MSD80 can take out one or multiple ignition coils & fuel injectors which will either show up right away or when applying boost. Another reason can be due to the injector values not being coded to the new DME. If you proved that all of the above are in good working condition and done, the last thing to address is your spark plug condition. Eventually, weak spark plugs can cause your engine to misfire, even enter limp mode when applying boost.
Based on the log if all above has been addressed, Fuel Low & Rail Pressure looks like it's dipping pretty low at some points while you're still accelerating which could contribute to it breaking up as you're describing. I didn't see any odd AFR's other than the normal spikes as you let off your pedal which don't indicate failing upstream/downstream O2 Sensors. However, I did see Bank 1 and/or Bank 2 approach the 15:1 mark occasionally, which is lean territory. This leads to a few reasons based on the Fuel Low-Pressure readings:
-Failing Low-Pressure Fuel Pump
-Failing EKP Module for the Low-Pressure Fuel Pump
If those have been addressed and you still break up pretty bad around the same point while having low readings Fuel Rail Pressure-wise, the next thing to be looking at is your High-Pressure Fuel Pump.
Again, this is just assuming based on experience along with no codes being mentioned. Let us know what your trouble codes are as soon as you can
Sometimes a failing MSD80 can take out one or multiple ignition coils & fuel injectors which will either show up right away or when applying boost. Another reason can be due to the injector values not being coded to the new DME. If you proved that all of the above are in good working condition and done, the last thing to address is your spark plug condition. Eventually, weak spark plugs can cause your engine to misfire, even enter limp mode when applying boost.
Based on the log if all above has been addressed, Fuel Low & Rail Pressure looks like it's dipping pretty low at some points while you're still accelerating which could contribute to it breaking up as you're describing. I didn't see any odd AFR's other than the normal spikes as you let off your pedal which don't indicate failing upstream/downstream O2 Sensors. However, I did see Bank 1 and/or Bank 2 approach the 15:1 mark occasionally, which is lean territory. This leads to a few reasons based on the Fuel Low-Pressure readings:
-Failing Low-Pressure Fuel Pump
-Failing EKP Module for the Low-Pressure Fuel Pump
If those have been addressed and you still break up pretty bad around the same point while having low readings Fuel Rail Pressure-wise, the next thing to be looking at is your High-Pressure Fuel Pump.
Again, this is just assuming based on experience along with no codes being mentioned. Let us know what your trouble codes are as soon as you can
There are no active codes which surprised me. The car is doing the same thing with the msd81 as it did with the msd80 with the exception that it would fry a Mosfet or two when it would do it. I will start with the plugs and if it continues, sounds like I will want to address the low pressure fuel pump. The injector values are correct. I did check those first. I am running index 9s
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