550i LCI throttle surge on tip-in
11-26-2014, 01:05 PM
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My Ride: 550i
550i LCI throttle surge on tip-in
Hi guys, very erratic and random gremlin of a problem I am trying to chase down here.
Car is a 08 550i (80k) with a sport-trans (brand new 15K miles).
On a quick throttle tip-in from a dead stop, so 1/3-2/3rds throttle depressed quickly, I am experiencing a serious amount of engine surging/hesitation. If I try to power through the surging with even more throttle, the engine results in even more surging. Kind of odd but the car sounds really loud as it is surging or louder than normal.
The only work around at the moment to remove the surging is to back completely off the throttle and ease back into the throttle normally and the surging is completely gone. I tend to encouter the problem more when starting on a hill as I use more throttle.
No CEL or anything else have popped up in the ECU. We pulled all the codes and nothing. No misfires recorded.
The list below includes things I have tried with zero results regarding the surging.
Removed the sprint booster and reverted to stock - no change
Reset the adaptive trans procedure - no change
Cleaned the air filter - no change
Cleaned the MAS - no change
Checked fuel pressure at the Rail - 50 PSI
Changed the pre-cat wide band O2 sensors - no change
New plugs - no change
I did have a new transmission installed which is leading me to think the car might need be reprogrammed by BMW again. This issue is simliar to my supercharged car with bigger injectors with an off the shelf tune.
Ideas?
What else should I be looking for or anything else I am over looking? This is driving me bananas!
Car is a 08 550i (80k) with a sport-trans (brand new 15K miles).
On a quick throttle tip-in from a dead stop, so 1/3-2/3rds throttle depressed quickly, I am experiencing a serious amount of engine surging/hesitation. If I try to power through the surging with even more throttle, the engine results in even more surging. Kind of odd but the car sounds really loud as it is surging or louder than normal.
The only work around at the moment to remove the surging is to back completely off the throttle and ease back into the throttle normally and the surging is completely gone. I tend to encouter the problem more when starting on a hill as I use more throttle.
No CEL or anything else have popped up in the ECU. We pulled all the codes and nothing. No misfires recorded.
The list below includes things I have tried with zero results regarding the surging.
Removed the sprint booster and reverted to stock - no change
Reset the adaptive trans procedure - no change
Cleaned the air filter - no change
Cleaned the MAS - no change
Checked fuel pressure at the Rail - 50 PSI
Changed the pre-cat wide band O2 sensors - no change
New plugs - no change
I did have a new transmission installed which is leading me to think the car might need be reprogrammed by BMW again. This issue is simliar to my supercharged car with bigger injectors with an off the shelf tune.
Ideas?
What else should I be looking for or anything else I am over looking? This is driving me bananas!
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