Slight hesitation on fly-by-wire throttle

[Bumpa]

The car is a 2002 Z3 2.2 Sport. It has the fly-by-wire throttle. Ever since I have had the car there has been a slight hesitation, probably less than a second, between pressing the pedal and getting an engine response. While this might not sound a lot, it makes smooth gear changes a bit tricky as it isn't easy to balance the clutch uptake with getting back on the throttle.

Even worse is reversing up the slope of my drive. I start off with a gentle press of the pedal, but as I go up the slope the revs drop off so I press a bit more, only nothing happens for a split second or so, and at that point the engine stalls. If I try to anticipate the drop off in revs and press a bit more early, suddenly the revs go shooting up and I feel like a novice.

Has this occured to others and if so what component is likely to be dodgy? It can't be intended to be like this.

 

[Lee]

There is a throttle sensitivity reset you can do: Copied from an E46 thread

Your engine computer programs your throttle response to fit your driving habits, so over time the car may lose the instant, aggressive throttle response it had from the factory. If you drive conservatively, the throttle eventually responds less aggressively, or someplace similar, where you can't drive the way you want. So try this if you want the throttle response restored to the more aggressive factory setting:

1) Press the pedal to the floor and keep it there until step 6 below.

2) Then insert the key.

3) Then turn the key to position "2". Position "2" is one position before the car engages and starts.

4) Wait 10 seconds and then turn the key back to position "0", which is the initial position.

5) Once again wait 10 seconds.

6) Then release the pedal.

7) Then press the pedal down and start the car up.

You should now have your throttle response reset. Your driving pattern from this point on will dictate how your throttle response adapts. If traffic congestion in your area forces you to drive conservatively a lot of the time, then over time your throttle response will once again become lacking, and you'll need to perform another reset (apparently once every 1-3 months, according to what I've read--I did this too recently to know for sure).

Failing this I would start looking for air leaks. A combination of these small vacuum leaks cause the same symptoms.
1) Intake boot rubbers
2) Disa O-ring
3) Rocker cover
4) CCV Lines

This should get you started

 

[Ianmc]

The "sender" on the pedal is known to fail with FBW. Preventative maintenance suggests replace every 50K miles.

 

[Bumpa]

The "sender" on the pedal is known to fail with FBW. Preventative maintenance suggests replace every 50K miles.

Hmm. A new one costs over £300. I can live with it in that case. I'll certainly try the software fix detailed by Lee. I've been through the intake side recently and think I have fixed any air leaks.

 

[Braz86]

Can't say I've noticed any issues with mine, but that's a great bit of info @Lee, I will definitely be doing the reset to see what happens