I have a 09 C2S
Every morning, for the first 30-45 second the car hesitates, not enough to throw a code, but enough to be felt by myself and passengers.
Took to dealer, first time they could not reproduce.
Second time, I left it there and they were able to reporduce.
As there were no codes. They contacted P NA.
They were told, get another similar car, make sure the other 911C2S does not do it in the morning when cold and if it does not. Then reprogram DME DFI.

What am I supposed to understand from this? Do we have a local hesitation zone? or are all P cars supposed to do this, is that what they think?

Not a problem, but annoying!
Anyone any experience?

 

PNA is diagnosing something over the phone and the car isn't throwing any codes to help them pinpoint the problem. Were it common the dealer would have told you so and would have known what to fix . Reprograming is a way to get the DME back to a factory "spec " and rules out software errors or any third party enhancements. If the problem goes away they'll chalk it up to software glitch. If not, and there are still no codes, they'll start replacing stuff till the problem goes away. Seems like a reasonable first step.

 

What you say makes sense, however it was not over the phone, it was through an intranet email type communication.
Will see and will keep you folks posted

 

So after having the car at the dealership for a week. They waited to get the exact same one, same year, same engine specs. They said both cars did the same in the morning (cold morning) for the first 30 seconds. They state that the cars run rich and that causes the hesitation, but it is within specs so that is why it does not throw a code

I am stumped!

 

Mine runs differently for the first 30-45 seconds too...I think this is totally normal. It s such a short period that it sounds reasonable to me. I also have the DFI.

 

Good. My warranty runs out in the summer. I wanted to make sure it is not coils or something like that
Thanks for your reply

 

So how cold are we talking here?

I have a 7.1 car so not sure if this is apples to apples, but as I understand it when the car first starts up it runs in open loop (hence rich) while the cats get up to temp, then it switches to closed loop and uses the O2 sensors.

Is it so cold the cats aren't warmed up when it switches to closed loop? I wonder if you wait another 30 secs or so after it switches to the closed loop program (you can hear the revs drop when it switches over) if you'll still have the problem?

Other things to look at would be the MAF and O2 sensors or air leaks past the MAF. But it's kinda hard to know where to start when it's not throwing codes.

 

Actually once the revs drop it does not hesitate.
So if I back out of the garage on a 32F day. Wait there 20-30 seconds and then drive off no hesitation at all. If I back out and start driving there is a minor hesitation which I can pick up. ( I guess I am ubersensitive).
So once it is on closed loop it does not do it anymore

 

I'll let other 7.2 owners chime in, but this makes more sense. Feedback controls are a wonderful thing.

 

Hi,
I had the same problem, early morning start up and the thing just hesitated for the first 5 mins. When I was cleaning the car I noticed my air filters were very black so got them changed and its been fine since. Doesn't make that much sense but worth a look, it's easy to see them . Mine is a 09 c2

Nick

 

that is normal on every car I own...... I wouldn t give it any more thought.

 

Yes thought of that in the summer, changed filters (air filters-engine), no difference