Not sure if this issue has ever got a conclusive answer but I'll bring it up again. I have been running my 2014 991.1S, with PDK, for the last two years and it has been a great running car on everything from short runs to cross country trips. I am running FVD mods including headers, Sport Exhaust, PDK tune and ECU tune. Car runs great at 3000rpm and up like a scared rabbit. Getting from a standstill to 3K, in either NORMAL or SPORT modes is OK but there is a noticeable hesitation/stumbling occurring. If you just drop the hammer, you're gone in a flash. The effect doesn't seem to as prominent when running in MANUAL but it's still there. I thought about uninstalling the current tune and reinstalling so the ECU forced to relearn. There was a new TB installed about a year ago and all service is up to date with no error codes ever showing.
I am going to schedule it in for service at Sewickley Porsche as Duane and his service team are second to none. Hopefully they can figure it out, if I can't solve it at this end. I know there has plenty of discussion on this forum about this peculiar behavior and hopefully I can get it resolved as it's really the only complaint I have about the car.

Thanks in advance for any information,

Tom in VA

 

I have a 2013 C2S, PDK, sport chrono plus and also have a very little blip that occurs about 2700 rpm. To me I would not really call it a hesitation, but it gets my attention because the power delivery is consistent otherwise. As you mention, others have mentioned this on various posts and I am not aware of any issues that have posted. I think it is the nature of the engine/drivetrain and does not really bother me. When my car is fully warmed up, oil temp 190+, I don’t notice it anymore. I have 20k miles on my car for perspective with no modifications.

 

Sometime it's more noticeable than others but yes I notice it as well.

There is a thread somewhere on this subject going back to 2014 I think.

 

+1 for me. I have this too on a 2013 CPO. had the Stealership check under warranty. They did not acknowledge the stumble was normal, only that they couldnt find anything wrong and advised to observe. it generally keeps happening in traffic. and yes power delivery has no issues

 

2016 C4 here stumbles when you first get on it. Most noticeable in Normal mode, but still present in sport.
New plugs and coils showed no improvement.
Always use minimum 93 octane.

Would love to hear a solution if there is in fact one.

Thanks

 

My only complaint is that mine shifts to 2nd a little more quickly than I’d like (except in Sport+ mode, which I don’t find usable in normal driving). I think that causes it to bog down just a little at around 2250-2500 RPM. Easily solvable with manual mode, but if there were a “hold 1st just a little longer” button I would press it.

 

My wife and kids refuse to drive my '16 991.1S because they are afraid of it. Ironically, Porsches IME come off underwhelming to people who are afraid of them, because as a driver you have to very clearly indicate to these cars that you want to go fast. Once you know how to, they're fast indeed. But if you just get in one and feather the throttle up and down the parkway it may not feel like much.

My wife's uncle is a Camaro/Vette guy. He drove the 991.1 once with me. He didn't say so but I could tell he thought it was slow. He also never got it above 3500 RPM because most guys don't climb into their nephew-in-law's sportscar and test the redline.

 

I have read one person stating they tried everything (plugs, coils etc.) and put in a new throttle body and that solved the issue. https://www.fcpeuro.com/products/por...ody-0280750473.

 

Have you had the recall performed to lower the Sport+ part-throttle shift points? That may be a good move in your situation, if you find that Sport mode isn't enough and Sport+ is too much.

 

Didn’t know that was a thing. Thanks, I’ll look into it.

 

There are definitely a few parts to swap out if you're willing to throw a little bit of time and money at these driveability issues:

• Throttle body ($150-200)
• Variocam solenoids ($400-450ish for the pair)

I have the 7 MT, but some of the stumble issues are similar between the two transmission types. The throttle body didn't help me personally, but the variocam solenoids solved like 90% of my stumble issues.

Both of the above items are pretty DIY-friendly. I did both with minimal difficulty.

 

The throttle body was upgraded last June so that’s one down. I’ll dig into the solenoids as I need to get it back on the lift for an oil change here quickly.
Thanks for the advice.

Tom

 

Did throttle body change help at all??

 

Did you calibrate the throttle body after reinstalling? If not, give that a shot.