Enwave
Well-Known Member
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- #1
Hey all --
I'm currently Ecutek tuned on an early batch 2020, 14k miles with about 1k on the tune with a very reputable tuner (don't wanna name so people don't incorrectly criticize since the problem seems completely unrelated to the tune and this tuner is AWESOME) on a flexfuel-only Reflex implementation (no PI for now). AA catted downpipe, CSF intake manifold, MST intake, Tomei single, just pretty basic bolt-ons except for the Reflex. Was on BM3 before the Ecutek tune for most of the first 13k miles.
The vehicle had been running great for a few of months on full E10-E50 range of flexfuel, then popped a boost leak that needed a new custom line from intake manifold to PCV. Got that done, drove it for about 100mi and things looked great again. I topped off some ethanol from our last station here in Utah that actually shut down a few days later (separate frustration) -- and after another 100mi of driving or so, I headed to get my rear PS4S swapped to ET Street S/S to hopefully regain some traction. About 30min into the drive, the vehicle started to lurch in stop and go traffic a bit a few times and then threw a few codes and went into limp mode (last code).
160020 - Crank shaft sensor: general loss of synchronization
160021 - Crankshaft sensor; Signal Implausible
21A127 - DFC_BMW_LHM_PROL_PWR_LIMD
Pulled up logs, cylinder misfire counter had incremented once for one cylinder. Pulled over, cleared codes, and tried to reproduce again, reproduced pretty quickly after that. My suspicion was that maybe that last batch of ethanol from the pump that shut down was waterlogged or bottom of the barrel stuff, so I actually drained the tank and replaced with pump, let it sit overnight after idling for a bit and tried again the next day just to see confirming that it was back down to E10/pump. Sure enough, 20-30mins later, same codes. Misfire was on a different cylinder each time. Cleared codes, tried to reproduce again, this time it was a really slow crank and eventually started, immediately throwing the codes with one more that I sadly didn't capture about the starter.
Decided to tow at that point, and let it sit in the garage for a few days while I spoke with a few people about the issue. Went to go start the car to try and reproduce the starter code, but it started perfectly and the codes had all self-cleared (which is pretty normal for these codes I think). Decided to take the car out to try and reproduce assuming that a single misfire wouldn't be a risk for any permanent damage. Drove around nearby surface streets/stop signs with no issue for almost exactly another 30mins, yet again a different cylinder misfire when the issue reoccurred.
I have reproduced two or three additional times, it's a 100% guaranteed issue at almost exactly 25-30mins. The car starts SUPER cleanly on cold start, but struggles some to start again after the codes are thrown until it cools down again. Have not seen the starter code pop up again.
I am curious if anyone has insight into this type of issue... or some pointers on where to look next. My thoughts:
TIA for any insight from folks who are a little more technical than I am!
I'm currently Ecutek tuned on an early batch 2020, 14k miles with about 1k on the tune with a very reputable tuner (don't wanna name so people don't incorrectly criticize since the problem seems completely unrelated to the tune and this tuner is AWESOME) on a flexfuel-only Reflex implementation (no PI for now). AA catted downpipe, CSF intake manifold, MST intake, Tomei single, just pretty basic bolt-ons except for the Reflex. Was on BM3 before the Ecutek tune for most of the first 13k miles.
The vehicle had been running great for a few of months on full E10-E50 range of flexfuel, then popped a boost leak that needed a new custom line from intake manifold to PCV. Got that done, drove it for about 100mi and things looked great again. I topped off some ethanol from our last station here in Utah that actually shut down a few days later (separate frustration) -- and after another 100mi of driving or so, I headed to get my rear PS4S swapped to ET Street S/S to hopefully regain some traction. About 30min into the drive, the vehicle started to lurch in stop and go traffic a bit a few times and then threw a few codes and went into limp mode (last code).
160020 - Crank shaft sensor: general loss of synchronization
160021 - Crankshaft sensor; Signal Implausible
21A127 - DFC_BMW_LHM_PROL_PWR_LIMD
Pulled up logs, cylinder misfire counter had incremented once for one cylinder. Pulled over, cleared codes, and tried to reproduce again, reproduced pretty quickly after that. My suspicion was that maybe that last batch of ethanol from the pump that shut down was waterlogged or bottom of the barrel stuff, so I actually drained the tank and replaced with pump, let it sit overnight after idling for a bit and tried again the next day just to see confirming that it was back down to E10/pump. Sure enough, 20-30mins later, same codes. Misfire was on a different cylinder each time. Cleared codes, tried to reproduce again, this time it was a really slow crank and eventually started, immediately throwing the codes with one more that I sadly didn't capture about the starter.
Decided to tow at that point, and let it sit in the garage for a few days while I spoke with a few people about the issue. Went to go start the car to try and reproduce the starter code, but it started perfectly and the codes had all self-cleared (which is pretty normal for these codes I think). Decided to take the car out to try and reproduce assuming that a single misfire wouldn't be a risk for any permanent damage. Drove around nearby surface streets/stop signs with no issue for almost exactly another 30mins, yet again a different cylinder misfire when the issue reoccurred.
I have reproduced two or three additional times, it's a 100% guaranteed issue at almost exactly 25-30mins. The car starts SUPER cleanly on cold start, but struggles some to start again after the codes are thrown until it cools down again. Have not seen the starter code pop up again.
I am curious if anyone has insight into this type of issue... or some pointers on where to look next. My thoughts:
- It could just legit be a bad crankshaft sensor
- I have had the car go into battery management after not being driven for awhile and it is on the original battery, perhaps it is near end of life
- Alternator looks fine in logs pegged at 15, but perhaps the sample rate is too low on the logs and I'm getting noisy output from the voltage regulator causing the sensor to lose power temporarily or the battery just can't keep up after 20-30mins
- The reflex is on the turbo side of the bay, back where people put small meth tanks under the little cover by the cowl. Perhaps the crankshaft sensor wiring from the reflex over to the other side into the ECU is running too close to the block or seeing interference, it's possible the path changed or something got bumped when fixing the boost leak. I'm no expert electrician but the ECU tap looks great so I don't think it is that.
TIA for any insight from folks who are a little more technical than I am!
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