[maatt]

Hi

been getting a few problems with my 340i (mppsk fitted, if that makes difference)

1. delay on accelaration from standstill (in sport mode), foot pushes onto accelarator but a delay of about a second before the car decides to start moving, feels like its in eco mode, but then all of a sudden it will just give you the full power you wanted initially (this is not foot to the floor accelaration, its just normal "i want to be off the traffic lights first" kind of acceleration)

2. car is doing a sort of jerkiness, in all modes, manual shift or auto, more noticeable in manual sport, 1/2 gear.
also happened in eco mode on motorway, cruisecontrol active @ 50mph, best way describe it is, it feels like the car is being pulled back a tiny bit.

have tried doing the throttle adaption reset to no avail.
its on the investigate job sheet for bmw when it goes in for first oil change but till then just want to ask if anyone has similiar problems.

[Londoner]

Originally Posted by maatt

Hi

been getting a few problems with my 340i (mppsk fitted, if that makes difference)

1. delay on accelaration from standstill (in sport mode), foot pushes onto accelarator but a delay of about a second before the car decides to start moving, feels like its in eco mode, but then all of a sudden it will just give you the full power you wanted initially (this is not foot to the floor accelaration, its just normal "i want to be off the traffic lights first" kind of acceleration)

2. car is doing a sort of jerkiness, in all modes, manual shift or auto, more noticeable in manual sport, 1/2 gear.
also happened in eco mode on motorway, cruisecontrol active @ 50mph, best way describe it is, it feels like the car is being pulled back a tiny bit.

have tried doing the throttle adaption reset to no avail.
its on the investigate job sheet for bmw when it goes in for first oil change but till then just want to ask if anyone has similiar problems.

Also a 340i with mppsk owner. Turbo lag is pretty good / not particularly noticeable with the b58 however there will always be a tiny bit of lag with a turbo charged engine. However what you're experiencing sounds different. You don't mention what throttle response is like in sports +? On mine there is lag on all modes bar sport +. If this mode didn't hold the gears so long i'd use it permanently. You can no doubt remap such things with bootmod etc.

Alternatively you could try a pedal box from racechip etc however reviews seem to be mixed - some swear by them, others are not impressed.

[maatt]

Originally Posted by Londoner

Also a 340i with mppsk owner. Turbo lag is pretty good / not particularly noticeable with the b58 however there will always be a tiny bit of lag with a turbo charged engine. However what you're experiencing sounds different. You don't mention what throttle response is like in sports +? On mine there is lag on all modes bar sport +. If this mode didn't hold the gears so long i'd use it permanently. You can no doubt remap such things with bootmod etc.

Alternatively you could try a pedal box from racechip etc however reviews seem to be mixed - some swear by them, others are not impressed.

I've never used sport+, I'll give it a go and report back.

I presume all this would be better visualized in logging software? I purchased mhd on black friday for future, but currently don't want to do anything if something is happening deep down.

any good free data logging software out there mobile or windows/mac? I've got the dkan cable etc.

[richatha]

I do have the same lag when pulling out myself and asked this question on here shortly after I got it and I think it's the gearbox / turbo lag which isn't great. You get used to it eventually but sometimes it catches me out but this is in comfort mainly.

I think it's to do with lifting off to approach junction and it going into coast mode. A blimp on the accelator before you stops helps. Also a cold engine also makes it worse.

Not had the other issue though and mines a March 18 car but no mppsk

[speedski]

Whats odd is that 'sort of jerkiness' sounds just the like EGR valve that I had replaced on my sootchucker recently....

[raptor14]

Did you try to reset the adaptation of the transmission already? Maybe that could help and you should at least feel a difference directly after the reset.

[James-335dx]

It could be an over active traction control? At least off the lights. I find mine tends to cut power, particularly in the wet and it feels like when you almost stall a manual off the lights. Would explain the lack of issue in Sport+ as it's wound back quite a bit.
The gearbox also adapts to your driving style so if your tootling along at 27mph and suddenly decide to do a 1/4 mile off the next set of lights you catch it off guard and it's seems to hesitate, like it's not ready

It can do it in the motorway too by not kicking down straight away.

Just a thought :

[jackstrath]

Cars tyres all ok ? I know you should have a warning if they are flat ect, but worth just double checking they are all in good condition

[rosstin]

#1 is almost certainly traction control. If you have lost traction in the last few minutes (very easy in a 340i this time of year) then the ECU will 'remember' and severely reduce power from a standstill, then once rolling give you the beans. Almost to the extent of feeling like something is broken. Pull over and turn ignition totally off should reset the memory.

[maatt]

Originally Posted by raptor14

Did you try to reset the adaptation of the transmission already? Maybe that could help and you should at least feel a difference directly after the reset.

Tried doing that numerous times, first try was gentle driving for a while after, second time, straight into normal driving style.

Originally Posted by James-335dx

It could be an over active traction control? At least off the lights. I find mine tends to cut power, particularly in the wet and it feels like when you almost stall a manual off the lights. Would explain the lack of issue in Sport+ as it's wound back quite a bit.
The gearbox also adapts to your driving style so if your tootling along at 27mph and suddenly decide to do a 1/4 mile off the next set of lights you catch it off guard and it's seems to hesitate, like it's not ready

It can do it in the motorway too by not kicking down straight away.

Just a thought :

lights go green, you push accelarator down about half, you move of at a snails pace, then all of a sudden with no additional foot movement, the car would wake up and go like you just kicked down. I've learned to expect it, so just end up lifting off a bit when it happens..

Originally Posted by jackstrath

Cars tyres all ok ? I know you should have a warning if they are flat ect, but worth just double checking they are all in good condition

tyres where 6mm all round last june, only done about 4k miles since then, but when it comes to replacement time Im sticking with the tyres I know gripped excellently on my mustang, so the runflats will be changed to pilot sports.

Originally Posted by rosstin

#1 is almost certainly traction control. If you have lost traction in the last few minutes (very easy in a 340i this time of year) then the ECU will 'remember' and severely reduce power from a standstill, then once rolling give you the beans. Almost to the extent of feeling like something is broken. Pull over and turn ignition totally off should reset the memory.

I'll have to put that too the test one night, since that sounds exactly the problem.

[Techno 9000]

Originally Posted by maatt

Hi

been getting a few problems with my 340i (mppsk fitted, if that makes difference)

1. delay on accelaration from standstill (in sport mode), foot pushes onto accelarator but a delay of about a second before the car decides to start moving, feels like its in eco mode, but then all of a sudden it will just give you the full power you wanted initially (this is not foot to the floor accelaration, its just normal "i want to be off the traffic lights first" kind of acceleration)

...

Sounds very much like the issue / characteristic I found with my 435D.
I would describe it in a very similar way. Having moved to the 435 from a diet of manual gearboxes I found it disconcerting.

I found it to be the gearbox deciding whether to move off in second, or drop into first. I learnt to use the gearbox on Sport / Manual mode (gear-lever left) when wishing to make a quick move off, its second nature to me now.

I would have thought that you having the DEC in Sport would overcome that (as it should default the car to move off in first), but it does depend on how Sport mode is configured in the iDrive.
Easiest way to find out if I'm on the money with your issue is to try the gearbox in Sport (gear-lever left) for a while and report back.

[jackstrath]

Originally Posted by maatt

tyres where 6mm all round last june, only done about 4k miles since then, but when it comes to replacement time Im sticking with the tyres I know gripped excellently on my mustang, so the runflats will be changed to pilot sports.

hope your kidding...

[maatt]

Originally Posted by rosstin

#1 is almost certainly traction control. If you have lost traction in the last few minutes (very easy in a 340i this time of year) then the ECU will 'remember' and severely reduce power from a standstill, then once rolling give you the beans. Almost to the extent of feeling like something is broken. Pull over and turn ignition totally off should reset the memory.

tested this last night, 100% true.