Acceleration 'lag/ delay'.

[Hi-Ho Silver]

C220 CDi SE Auto. 7,000 miles.

For example: I'm waiting stationary at a junction or lights. Regardless of whether I have placed the auto box in Park or not, when I depress the accelerator pedal, from standstill, there's a one to two second delay before the car starts to move.

Something similar happens when the car is moving at any speed and sometimes the engine revs increase but road speed doesn't.

Any ideas for why this happens? It hasn't suddenly developed and you can call me weird if you like but the reasonable expectation is that the car moves when the pedal is pressed.

Does anyone have experience of this or a possible cure for it apart from 'press the pedal two seconds before the car in front starts to move'? Will a remap help or cure this?

Muchas G's, Hi-Ho.

 

[panason1c]

It seems that it is 'normal' for the delay, my ML does it also and it can be quite entertaining when trying to enter a busy roundabout or quickly pull out of a junction.......you will indeed acquire the art of 'pressing the pedal 2 seconds before you need to move'....

I find that a steady press of the pedal gives a better response than the much longer delay i get when 'flooring' it.

I've read reports that remaps do improve this........

 

[jjustme]

Not sure if this is relevant or if C class have the C/S button, but have you tried it if it does?

Mine has a S/W button, and when it's in W, from the lights, initially it just revs and moves very slowly off the line compared to S mode which has a much faster start with a lower rev.

 

[silver_star]

Not sure if this is relevant or if C class have the C/S button, but have you tried it if it does?

Mine has a S/W button, and when it's in W, from the lights, initially it just revs and moves very slowly off the line compared to S mode which has a much faster start with a lower rev.

That will be because "W" is a 2nd gear start (Unless you plant it and use kickdown) and "S" is a 1st gear start.

 

[steve333]

C220 CDi SE Auto. 7,000 miles.

For example: I'm waiting stationary at a junction or lights. Regardless of whether I have placed the auto box in Park or not, when I depress the accelerator pedal, from standstill, there's a one to two second delay before the car starts to move.

Something similar happens when the car is moving at any speed and sometimes the engine revs increase but road speed doesn't.

Any ideas for why this happens? It hasn't suddenly developed and you can call me weird if you like but the reasonable expectation is that the car moves when the pedal is pressed.

Does anyone have experience of this or a possible cure for it apart from 'press the pedal two seconds before the car in front starts to move'? Will a remap help or cure this?

Muchas G's, Hi-Ho.

Hi,search turbo lag,you can get a device called a sprint booster which improves throttle response if it irritates you enough.

 

[alexis.jones]

I have a sprint booster fitted to my C320 CDI and it made a big difference

 

[Beardz]

How much do sprint booster run out at and how difficult are they to have fitted?

Is your 320 cdi a V6?

 

[withabix]

£175ish and about 10 minutes allegedly.

 

[rascalmaster]

read loads of discussions about the possible dangers of using a sprint booster... best do your research b4 you get one of them...

also read a 'white paper' which concluded that there wasn't much gain... and a large flat range near the top...

 

[Rory]

C220 CDi SE Auto. 7,000 miles.

Does it have the 7 speed box, or is it still a 5 speed?

 

[renault12ts]

Whether in W or S my car just goes when I hit the throttle. There must be something wrong, a second or two is a big lag.

 

[panason1c]

Looks like the OP has gone?

 

[Hi-Ho Silver]

Still here folks. Work takes me away for days at a time.

Okay so... i've heard mostly negative reports of sprint boosters and regardless of them, i'd prefer to be able to correct this 'lag' by other means.

'W' stands for 'Winter' mode. It is, as another person said earlier, a way of allowing your auto box to start from standstill in 2nd gear so as to avoid possible wheelspin. My old CLK had rear wheel drive and that's not a lot of fun unless you really do enjoy fish tailing around residential streets. 'S' stands for 'Standard' mode and this starts the car in 1st gear. I may be wrong but I also think the settings affect kickdown ie whether the car kicks down 1 or 2 gears but please check this for yourself.

I'm going to have a chat with the guys at Angel Tuning about this to see if they can do anything to help me out.

My C220 has 5 gears and although i'd prefer a slightly different ratio here and there, it does the job well with 5 gears. It also has an 'E' for 'Economy' and 'S' for 'Sport' mode. 'S' holds the revs for longer before changing gear either way but I find that there are 'sweet spots' in the box and when I match both engine and road speeds correctly, the gearbox sings.

Many thanks for the replies folks and apologies for taking so long to reply to you.

His Holiness H.H. Silver

 

[markjay]

Search here for 'Delay before acceleration'... they all do that

I found that depressing the accelerator gently first and relying on low-end torque rather than revs, does prevent the delay, though the acceleration is more gradual than had been hoped for, and at any rate relying on low-rev torque on a 180K does require a leap of faith... but depress the accelerator fast and hard and the car will ponder about it for a while before taking any notice.

 

[Hi-Ho Silver]

Hmmm... think i'll mention this to MB UK to see if there's any way they can ensure this nonsense of ICU programming is dealt with. I see no reason for why a string of C++ should stand in the way of driving safely. Bit difficult to connect with my car when it pops out for a fag every time we stop at the lights. Leaving it in 'Drive' with my foot on the brake, is counter intuitive to me.

 

[mobeyone]

Search here for 'Delay before acceleration'... they all do that

I found that depressing the accelerator gently first and relying on low-end torque rather than revs, does prevent the delay, though the acceleration is more gradual than had been hoped for, and at any rate relying on low-rev torque on a 180K does require a leap of faith... but depress the accelerator fast and hard and the car will ponder about it for a while before taking any notice.

I agree and I think the delivery is actually better than planting your foot for the kickdown.

One too many gears that 7g box for my liking....

It would be nice for the next gen 7g to have an option to switch from 5-7 depending on use. I dont see the need of 7 gears for town use.

 

[Dieselman]

Leaving it in 'Drive' with my foot on the brake, is counter intuitive to me.

It's the correct way to drive an automatic.

 

[Hi-Ho Silver]

It's the correct way to drive an automatic.

I'm interested to know why you believe this is the best way to drive.

My attitude is based on transferring the accepted wisdom of driving a manual box. Stop, Handbrake on, Neutral (and my foot is usually on the brake pedal at this point because when i'm putting the car into 1st or 2nd and the handbrake comes off, my foot would need to be on the foot brake). I follow this notion (using 'Park' instead of 'Neutral' in my auto) because I seem to recall this being a safer practice, than leaving the car in any gear (also need to keep the clutch disengaged) or 'Drive'.

Whatever the accepted practice, the lag which occurs between depressing the accelerator and the car moving, is anything but reasonable.

Perhaps the Class 1ers or Advanced drivers could shed some light on this?

Hi-Ho

 

[renault12ts]

Leave it in drive.

 

[Dieselman]

The delay is just the gearbox valves operating and pressurising the clutches, which since oyu keep taking it out of gear will be slipping and wearing everytime you engage drive.

The correct way to drive an auto is to leave it in D, but it's your car, your frustration and your wallet...