What is the current state of the 'engine stumble' issue?
#391
It's so hard to say what might be happening. The new solenoids are revision 03, the original ones in my 2013 MY (2012 production date) car are an 02 revision.
They definitely didn't look amazing, but at the end of the day there is oil circulating through there, so I think that is probably to be expected.
The stumble was present for me regardless of ambient temp, or engine temp for that matter.
They definitely didn't look amazing, but at the end of the day there is oil circulating through there, so I think that is probably to be expected.
The stumble was present for me regardless of ambient temp, or engine temp for that matter.
#392
Well, that didn't take long. My stumble has been back again for the past couple of months. There are times when the car runs absolutely smoothly, and then other times when it feels like it is bucking back and forth as if you're coming off the clutch improperly.
It was really jerky and terrible early this morning, and then on my drive back home later in the morning, it ran 100% perfectly.
It was really jerky and terrible early this morning, and then on my drive back home later in the morning, it ran 100% perfectly.
#393
Collectively, over time, stumble sufferers have replaced almost every conceivable engine component to no avail. The fact that the problem usually reoccurs in short order seems indicative of the DME/ECU quickly re-learning its bad behaviors.
At the risk of sounding like a conspiracy theorist, what are the chances that this is possibly caused by or related to the current Porsche emissions "scandal." Porsche has allegedly altered hardware and software involved with emissions testing, and one can only wonder if a bug is hidden deep within the ECU.
One thing is sure .......... We're unlikely to ever know.
At the risk of sounding like a conspiracy theorist, what are the chances that this is possibly caused by or related to the current Porsche emissions "scandal." Porsche has allegedly altered hardware and software involved with emissions testing, and one can only wonder if a bug is hidden deep within the ECU.
One thing is sure .......... We're unlikely to ever know.
#394
Collectively, over time, stumble sufferers have replaced almost every conceivable engine component to no avail. The fact that the problem usually reoccurs in short order seems indicative of the DME/ECU quickly re-learning its bad behaviors.
At the risk of sounding like a conspiracy theorist, what are the chances that this is possibly caused by or related to the current Porsche emissions "scandal." Porsche has allegedly altered hardware and software involved with emissions testing, and one can only wonder if a bug is hidden deep within the ECU.
One thing is sure .......... We're unlikely to ever know.
At the risk of sounding like a conspiracy theorist, what are the chances that this is possibly caused by or related to the current Porsche emissions "scandal." Porsche has allegedly altered hardware and software involved with emissions testing, and one can only wonder if a bug is hidden deep within the ECU.
One thing is sure .......... We're unlikely to ever know.
#395
#396
#397
Anyone here had or have the experience of a stumble when lifting *off* of throttle between 3500-4k RPM on semi aggressive driving?
Maybe in 2nd gear, and/or 3rd? Below that RPM range, or above it no stumble at all..
Maybe in 2nd gear, and/or 3rd? Below that RPM range, or above it no stumble at all..
#398
A quick data point here and a link to another thread, which prompted me to try one more part swap.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
#399
A quick data point here and a link to another thread, which prompted me to try one more part swap.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
BTW, any tips for avoiding the sensor clip damage? Thanks.
#400
Sounds very promising! Assuming this is in fact the fix, it's surprising that it turns out to be a relatively benign solution. I had assumed the problem was so deeply embedded in the ECU that it was hopeless. I've got the part on order, and am hoping the new part doesn't come with the current malfunction.
BTW, any tips for avoiding the sensor clip damage? Thanks.
BTW, any tips for avoiding the sensor clip damage? Thanks.
My best advice on not breaking the sensor clip is to just not be me - I am extremely skilled at breaking these things. Just take your time and try to wiggle it free with a small flathead screwdriver. I made the mistake of trying to hold it with a pair of needle nose pliers and I squeezed a bit too hard.
#401
A quick data point here and a link to another thread, which prompted me to try one more part swap.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
https://rennlist.com/forums/991/1207...itation-3.html
I happened upon a 2016 GT4 throttle pedal (same part number as the 991.1 throttle pedal). It was only $99 shipped, so I figured I didn't have a lot to lose. (Part number, btw, is 970.423.019.01)
I received the 2016 GT4 throttle pedal a few days ago. My cul-de-sac is still half snow/ice, but I decided to get the car out yesterday regardless. I knew there was a reason I got these crappy all-season tires
I drove it yesterday with the original throttle. Definitely, some stumble/hesitation as I typically find on most drives. I then parked back in the garage and swapped the throttle pedals out (easy job, other than I am extremely good at breaking clips, which I ended up doing with the sensor clip). I did the throttle reset procedure as I figured that might be a good step.
Today, I drove the car for about an hour. I could not reproduce the stumble in any way, shape or form no matter what I tried.
Only time will tell of course, but that was one of the most enjoyable drives I've ever had in the nearly 6 years that I've owned my 911.
#402
Put the key in the ignition and turn it to "on" (without starting the engine). Wait about 30-45 seconds and you'll hear the throttle plate make some noise. That's it!
Also, I've now done about 800-900 km since swapping the throttle pedal and I'm happy to say that the car has been driving great. I've still felt the stumble a couple of times, but it was far less noticeable. I'm merely used to how it feels so even a slight hesitation in that range gets my attention.
Also, I've now done about 800-900 km since swapping the throttle pedal and I'm happy to say that the car has been driving great. I've still felt the stumble a couple of times, but it was far less noticeable. I'm merely used to how it feels so even a slight hesitation in that range gets my attention.
#404
edit - I've also tried:
- replacing the variocam solenoids
- throttle body replacement
- throttle reset countless times (nearly every drive)
- different fuels and fuel grades
Last edited by koala; 05-28-2023 at 07:36 PM.
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#405
As far as I am concerned, the replacement throttle pedal *is* the cure.
edit - I've also tried:
edit - I've also tried:
- replacing the variocam solenoids
- throttle body replacement
- throttle reset countless times (nearly every drive)
- different fuels and fuel grades
P.S. - I'd like to see a Porsche tech remove the sensor clip without breaking it. Mine did not survive the process.