Car revving

sowbmw · 10-23-2018, 08:59 AM

I know this has been discussed many times and the common issues could be HPFP failure, injector leakage or the car is need of a software update.

However, I have an n55 and the car usually revs up and down during starts, and occasionally it will struggle to rev up and down (almost as if it will stall) for about 20-30s. Afterwards though, the car is perfect, no engine lights, no idle issues and no driveability issues.

I tried resetting the throttle adaptations by using the 'foot to pedal' method. After the procedure, and to my surprise, the car did not rev up and down. I figured it was fixed. So i drove it home, switched it off then came back several minutes later only to find the problem has resurfaced, but nowhere near as bad as before the throttle reset procedure.

This morning, I went to turn the car on (after sitting overnight) and again no revving up and down.

I'm not too sure what this could be. Do the adaptations need to be reset using INPA? Maybe a software update? or something else?

Thanks for your help

Pladi · 10-23-2018, 09:15 AM

The adaptations could mask the issue in a way temporarily. It doesn't mean you might not have like vacuum leak issues.. OR a bad MAF sensor.. those are common culprits for bad idle.. could also be your O2 sensor. These dont always throw codes but check BMW codes first. A SW flash rarely fixes real idle problems..

As far as adaptations there are many more not just throttle.. yes use a BMW tool to do that. I dont think those will help unless you have replaced a part recently and the issues started.

Fritzer · 10-23-2018, 02:34 PM

How many miles? Might consider looking into walnut blasting, I heard that this issue can come up on N54s in a similar way.

sowbmw · 10-24-2018, 08:13 AM

It has 114000 miles. It's strange cause the issue presents itself when i drive it for a while, then switch it off, and turn it back on within 10min to several hours after switching it off. But if i leave it overnight and do a cold start, then car down't rev up and down.

I've looked at the eccentric shaft actuator diy and the hpfp thread. Is there a definite way to diagnose these parts without any codes being thrown.

10-23-2018, 08:59 AM	#1
sowbmw Enlisted Member 15 Rep 47 Posts Drives: silver bmw 335i Join Date: Mar 2016 Location: Toronto iTrader: (0)	Car revving I know this has been discussed many times and the common issues could be HPFP failure, injector leakage or the car is need of a software update. However, I have an n55 and the car usually revs up and down during starts, and occasionally it will struggle to rev up and down (almost as if it will stall) for about 20-30s. Afterwards though, the car is perfect, no engine lights, no idle issues and no driveability issues. I tried resetting the throttle adaptations by using the 'foot to pedal' method. After the procedure, and to my surprise, the car did not rev up and down. I figured it was fixed. So i drove it home, switched it off then came back several minutes later only to find the problem has resurfaced, but nowhere near as bad as before the throttle reset procedure. This morning, I went to turn the car on (after sitting overnight) and again no revving up and down. I'm not too sure what this could be. Do the adaptations need to be reset using INPA? Maybe a software update? or something else? Thanks for your help
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10-23-2018, 09:15 AM	#2
Pladi Lieutenant Colonel 718 Rep 1,753 Posts Drives: 2011 335i xdrive Join Date: Nov 2017 Location: Waterloo, ON Canada iTrader: (0)	The adaptations could mask the issue in a way temporarily. It doesn't mean you might not have like vacuum leak issues.. OR a bad MAF sensor.. those are common culprits for bad idle.. could also be your O2 sensor. These dont always throw codes but check BMW codes first. A SW flash rarely fixes real idle problems.. As far as adaptations there are many more not just throttle.. yes use a BMW tool to do that. I dont think those will help unless you have replaced a part recently and the issues started.
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10-23-2018, 02:34 PM	#3
Fritzer No one sleep in Tokyo 945 Rep 1,507 Posts Drives: 2011 E90 328i//1995 E34 530i Join Date: Oct 2018 Location: San Diego, California -> Austin, Texas iTrader: (3)	How many miles? Might consider looking into walnut blasting, I heard that this issue can come up on N54s in a similar way. __________________ 2011 E90 328i, 1995 E34 530i, 1992 E32 740i, 1991 E34 525i
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10-24-2018, 08:13 AM	#4
sowbmw Enlisted Member 15 Rep 47 Posts Drives: silver bmw 335i Join Date: Mar 2016 Location: Toronto iTrader: (0)	It has 114000 miles. It's strange cause the issue presents itself when i drive it for a while, then switch it off, and turn it back on within 10min to several hours after switching it off. But if i leave it overnight and do a cold start, then car down't rev up and down. I've looked at the eccentric shaft actuator diy and the hpfp thread. Is there a definite way to diagnose these parts without any codes being thrown.
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