991S PDK throttle hesitation from start
 

Have a May'12 build 991S, PDK, S-Chrono, S-PASM, 11k km. Now that summer weather has arrived, and driving-like-I-stole-it whenever possible, a throttle hesitation issue has come up.

On fast acceleration from a stop, the initial few hundred RPM's from idle, there is a hesitation. This is in manual or auto, Normal, Sport or Sport Plus.

Smooth application of throttle from start, this does not happen, but only when I hit the throttle as to get into traffic quickly. I haven't tried hitting the kick down button in this way as generally getting into traffic entails a 90 degree turn and I'd initiate a spin.

I've tried a left foot on brake pedal and raising throttle to 1,500 rpm type launch but that is not practical.

What is your experience?

Exact same for me (991-4S PDK). There is maybe a 1 second (?) lag when the accelerator is depressed aggressively from a stop when it feels like nothing is happening.

I just recently figured out that smooth application doesn't give you that lag but haven't played with it enough to figure out if I like that approach better.

I saw that thread at the time but not the end of it where it talks about the lag from a start so thanks for the link. FWIW I've never noticed an issue in 2nd gear or in the 2,500-3,000 rpm range. Interesting.

Made this video today to try to demonstrate the throttle response or acceleration hesitation issue.

I have the same car and have not noticed it... although compared to my Cayenne diesel with all the low end torque, the 991S seems slow at low rpm. I chalked it up to being a low torque, high rpm engine. Maybe a software tweak can fix it for you. I couldn't really see it in your video, I guess because I can't see the tach or your accelerator pedal.

Nice troubleshooting video.

Now, have you taken the service manager at the dealership for a ride to demo it to him?

I do notice the relatively low torque of the 991S before about 2,500 rpm at which point it comes alive. This is much before that at 900 rpm. I was concerned as well that the acceleration hesitation would be hard to see on the video. I'll try your suggestion - video of the tach and pedal.


Have an appointment July 18.

Let us know what they say. I chalked it up to PDK feathering the clutch to avoid excessive wear.

It is an automatic manual. Would you expect that feeling if you were releasing the clutch?

I know most here love their PDK 991's but I highly recommend a test drive in a 6 speed automatic corvette for a reminder of what a sports car that jumps off the line from idle feels like!

Good point. Definitely would not expect it...but beats me how a computer does it ;)

you nailed it right.many po owners found that out the hard way when they pulled up to a vette at a traffic light:bowdown::bigbye:

I had the update performed last Friday and have noticed the same thing. Immediately upon acceleration, there is a slight hesitation before the vehicle actually gets going. I've noticed this in all modes.

I think 911 owners are well aware their car is NOT a drag racer (read American Muscle) and more of an overall package (handling in addition). Don Garlits I'm not looking to be... Emerson Fittipaldi maybe...