Odd Acceleration Issue

Akopley · 06-24-2011, 01:29 PM

So I am scheduled to bring my car in Monday for service due to repeated limp modes at WOT. I had the issue about a month ago when I first installed JB4 and it threw a vanos code. I had the car serviced and replaced the vanos and wastegates, updated software and replaced fuel pumps due to a the recall that the previous owner had never taken care of. I was hesitant to have this done because other than a few limp modes and the vanos code the car had been running smooth as silk. When I got the car back it feels very different. When I accelerate hard instead of being a smooth pull it seems like it is tugging...or pulling off and on. When I put the JB4 back in this made the pulls smoother but I could still notice that the acceleration wasn't as consistent and it seemed that it was "wavering". I really don't know the proper term to explain what I am feeling but my roommate and coworkers who ride with me can feel it too. They are still surprised at the speed but they notice the lack of smoothness.

I just spoke with my service tech (great guy) and tried to explain to him what was happening. He said it might be the turbos but hadn't heard of the issue before. When I switch the jb4 to stock setting it is extremely apparent. I am going to pull out the JB4 and DCI before service obviously but I wanted to see if anyone had experienced anything like this before and what the solution was. I am open to opinions as well.

Thanks,

Adam

pzco · 06-24-2011, 01:41 PM

chaned my vanos solenoids. my car seems to be doing same thing although it has tapered out some what. almost a slight surging or lurching mostly 1st and 2nd gear. no clue but it does run faster now. go figure.

Akopley · 06-24-2011, 01:55 PM

Yeah don't get me wrong it still feels fast as hell especially with the JB4 boosting up the turbs. I wouldn't even care if i wasn't getting the limp on the highway. I was having a spirited time with an S65 until I got reduced power. I got on the phone with BMW minutes after and made the monday appointment.

06-24-2011, 01:29 PM	#1
Akopley Second Lieutenant 16 Rep 209 Posts Drives: 335i coupe Join Date: May 2011 Location: Atlanta iTrader: (3)	Odd Acceleration Issue So I am scheduled to bring my car in Monday for service due to repeated limp modes at WOT. I had the issue about a month ago when I first installed JB4 and it threw a vanos code. I had the car serviced and replaced the vanos and wastegates, updated software and replaced fuel pumps due to a the recall that the previous owner had never taken care of. I was hesitant to have this done because other than a few limp modes and the vanos code the car had been running smooth as silk. When I got the car back it feels very different. When I accelerate hard instead of being a smooth pull it seems like it is tugging...or pulling off and on. When I put the JB4 back in this made the pulls smoother but I could still notice that the acceleration wasn't as consistent and it seemed that it was "wavering". I really don't know the proper term to explain what I am feeling but my roommate and coworkers who ride with me can feel it too. They are still surprised at the speed but they notice the lack of smoothness. I just spoke with my service tech (great guy) and tried to explain to him what was happening. He said it might be the turbos but hadn't heard of the issue before. When I switch the jb4 to stock setting it is extremely apparent. I am going to pull out the JB4 and DCI before service obviously but I wanted to see if anyone had experienced anything like this before and what the solution was. I am open to opinions as well. Thanks, Adam
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06-24-2011, 01:41 PM	#2
pzco Enlisted Member 0 Rep 31 Posts Drives: 2007 alpine white e92 Join Date: Jun 2011 Location: colorado springs iTrader: (0)	chaned my vanos solenoids. my car seems to be doing same thing although it has tapered out some what. almost a slight surging or lurching mostly 1st and 2nd gear. no clue but it does run faster now. go figure.
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06-24-2011, 01:55 PM	#3
Akopley Second Lieutenant 16 Rep 209 Posts Drives: 335i coupe Join Date: May 2011 Location: Atlanta iTrader: (3)	Yeah don't get me wrong it still feels fast as hell especially with the JB4 boosting up the turbs. I wouldn't even care if i wasn't getting the limp on the highway. I was having a spirited time with an S65 until I got reduced power. I got on the phone with BMW minutes after and made the monday appointment.
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