I am experiencing a slight issue with my new Rapide S. Since new (by now car has run 600 km) I would experience a rough idle for about 10 seconds at cold starts. Engine idles rough and seems to stutter and wont acccept accelerator Input. After 8-10 seconds it settles and all is fine.
Later warm starts do not exhibit any issues and car starts normal, only to do the same and the next cold start a day later after it had settled over night.


I took the car to the dealer who could not pull any codes and updated to the latest ECU Software to no avail. The issue remains.


Other than that, the car runs jut perfect an exhibits no Anomalie at all.


Any ideas ?

 

Are you using the same fuel supplier?

Perhaps there is an issue with the quality of the fuel you are using since no codes are being presented?

 

DonL, I have used different suppliers. There was a AM campaign concerning the rough idle at cold start. My dealer supposedly updated to the latest Software that should take care of that Problem.


Unfortunately the issue has still not been resolved.


Furthermore, I believe that if it was fuel related, it would exhibit the same issue at any start not just at cold starts.

 

My 2009 DBS did this recently. Rough idle on cold start, by the time I got to work the engine was running smoothly. Did this off and on.

It finally threw a code. P0174. I thought either dirty MAF or sticky/dirty fuel injector. I ruled out the MAF because of the off an on nature of the rough idle/misfire. (Long story of reasoning behind this) I cleared the code and put a bottle of fuel injector cleaner with last tank of gas and have just about used that up. Have not experienced the issue since.

Your 2014 is 5 model years newer so I don't know exactly what your issue is. But a bottle of fuel injector cleaner is fairly inexpensive. You might try it.

 

thanks for the Input. my issue seems very similar to yours. however, it showed this from new (30kms on odo) so i doubt it is mechanical/electrical and am leaning more towards ecu. my dealer said they willreflash the ecu....will come back with update..

 

A fuel with minimal (or lacking) "light fractions" would not vaporize easily on a "cold start" whereas once the engine was warm, it would behave ok.
With only 600km's or so, you still could have some "poor" fuel remaining in your tank.

 

Hi @intouch1, have you found the reason? Looking for some suggestion to my similar case (Vanquish 2013 MY). Thanks!

 

Run a bottle or two (depending the size of the bottle) of Techron through the gas tank

 

Hmm, just replaced all 12 x coils, plugs and injectors. All new.

 

I use a bottle of Techron about every 2000-3000 miles.