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M2 Technical Topics > N55 Engine / Drivetrain / Exhaust / Bolt-ons / Tuning > Boost cut/Fuel cut? HELP!

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      03-17-2021, 11:30 PM   #1
FattyBoy
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Boost cut/Fuel cut? HELP!

Recently I installed a catless downpipe, chargepipe, FMIC, and running the BM3 OTS stage2 ACN map. While doing some pulls I've noticed the rpm stop around 6K-ish as if the clutch is slipping. I am fairly certain it isn't the clutch as I am only at 12k miles. Is it possible I have a boost leak? The chargepipe has a decent amount of wiggle over the throttle body and intercooler coupling. Any advice on what to check? I've attached a datalog but it isn't the best. I can get another if needed. Any help is much appreciated. Thanks for reading.

https://www.bootmod3.net/log?id=6052...vNkue1Mefp2OP8
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      03-18-2021, 01:33 AM   #2
Dj_Quik
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lots of things are happening in your log from what i can tell. first of all, did you turn off DSC when you logged? you have throttle cuts right off the bat.

but i think your biggest issue is that your fuel pump took a dump real hard. I recall mine dipping as low as 1500, but yours is even lower at 1100 psi. i have since changed to a dorch pump and that issue is gone. im afraid you probably need a new fuel pump. id advise you not to go WOT anymore or go back to stock tuning until you figure out your fuel pump issue because you run the risk of misfires and running super lean.

your fuel quality could be an issue as well. but thats a moot point for now until you can figure out the fuel pump issue.

as far as the throttle closures at tip in, could either be your dsc was on or you are having the same issue as i am with throttle closures. im thinking its probably due to the combination of the catless downpipe and the pressure change due to the larger intercooler. although yours closes and opens multiple times whereas mine just closes once briefly for about 300 rpms at tip in and then gives me full throttle again all the way to redline.
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      03-19-2021, 12:13 AM   #3
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DSC was on. I reinstalled the stock downpipe and went with the stage 1 ACN tune and there is no more fuel cut! I guess this is as far as I go mod-wise haha. Appreciate the help!
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      03-19-2021, 12:46 AM   #4
Dj_Quik
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Glad it worked out!
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