Accelerator lag

johnp · Post by **johnp** » 05 Jan 2011, 13:12

Hello, I've just purchased a 2003 XC90. When I set off after starting up and putting it into drive mode. The car doesn't move off in relation to when I depress the accelerator. There seems to be a delay for 3 or 4 seconds and it's sluggish. I depress the accelerator more then it seems to jump into high revs and wants to fly !!
Any other car I've ever driven responded in equilibrium to the amount of pressure applied to the pedal. It also seems slow to respond when I wish to accelerate to overtake.

Is thier something I should be aware of or is there a fault I need addressing

Thanks for any advice offered

John

TexasCoder · Post by **TexasCoder** » 06 Jan 2011, 03:37

I have a 2004 XC90, and notice the same thing. When driving my other car, 2002 Dodge Intrepid, I notice an immediate pedal to movement ratio. From what I have been told, and what I have read on other blogs, this appears to be due to the "drive by wire" technology used in newer vehicles.

Older vehicles, as in my 02 Dodge, has a physical cable that goes from the gas pedal to the throttle body. When the pedal is pushed, the throttle is immediately engaged. With the "Drive by Wire" (ECM controlled and monitored pedal), the ECM determines the amount of throttle engaged. The slower you push the pedal, the slower the throttle engages, and so on. Try stomping on it, and you should notice that the car reacts quickly.

I also have a theory this has to do with the anti-slip and traction control in the XC90, regardless of the "W" winter mode being engaged.

Just my two cents...

johnp · Post by **johnp** » 06 Jan 2011, 09:24

Hi there and thank you for your input.

That makes a great deal of sense although the trouble with 'stomping' as you put it tends to make it over rev and can't be much good for the consumption can it ?

Either way that's the best theory I've heard so far, so thank's again

John

Post by **stone36** » 08 Jan 2011, 10:02

Basic question would be what is the tune-up condition of there car? regular maintenence? have the plugs ever been changed etc.? That could cause some issues. Also what engine do you have 5cyl or T6?

I don't know if this would have anything to do with it or not but could be related to the turbo control valve. Read here about what it does and symptoms of failing.

Good luck

johnp · Post by **johnp** » 10 Jan 2011, 05:47

Thank you for that
I believe the car to be serviced fully as I've just purchased it !! The log book shows good service history, however not always by a Volvo dealership !! I believe its the 5cyl 20 valve 2.5 model. I shall continue my investigations

Thanks again
John