E39 V8 Slight delay or stall after flooring the throttle

[NineOneSeven]

Hi chaps,

My brother recently bought a low milage E39 535i steptronic its a great carwith many M options such as seats, wheel and suspension. A nice healthy 245bhp with a nice torque curve and a V8 rumble.

We sped away from a set of lights and found that there seemed to be a delay before the car responded with forward motion. Quite odd, so to check this out we tried a determind getaway off of the next lights to see what was happening. Again the car did nothing and then sunddenly came on after a delay.

Our next experiment was a full foot to the floor launch. The car just stalled. We didn't hold the car on the brake and build up revs or anything.

We didn't notice any ACS lights coming on or anything like that. Also when away if you depress the throttle purposefully the car does respond and also the kickdown works great.

Incidently I tried the same thing in my wifes E46 328i steptronic and it is pretty good pulling away but it also didn't like the floored throttle from standing. It also fluttered before storming on.

Its not too much of a bother as he doesn't race at the lights but there are times when you need to make a swift getaway from the lights. The stall doesn't inspire confidence.


Can anyone shed some light of the issue?

[8Tech]

You are experiencing the electrical delay, (lag), between physical input and electrical response from the system. Not unusual and difficult to quantify without driving it but it sounds normal, if not ideal.

BRING BACK CARBS AND THROTTLE CABLES!

[NineOneSeven]

I thought that they were still had cables operating the throttle. Are you saying its a fly by wire vehicle?

What do you think caused the car to stall..? I realise it would be a best guess.

Many thanks.

[Neil.D]

i would start on the MAF sensor. I have covered it a few times,

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

N

[NineOneSeven]

Thanks.