logray

edit: It looks like the information in blue below from Porsche is a documentation error. When segment A & B are near 1(.000) and wheel learning prog is near 0(.000) adaption is complete and the flywheel is OK (from a reference mark perspective). I believe if wheel is over 0.0005 that may still indicate a problem with the flywheel or flywheel sender which would probably cause a check engine light. Feel free to continue to provide your numbers to compare with other owners

need your help.

Manual gearbox owners:

If you have just a couple minutes with your Durametric (or PST2/PIWIS), and your car idling, can you read out these three "Actual values" for me and post them here?

Segment (A)
Segment (B)
Learn. progress sens. wheel adapt.

Also please include the version of Durametric you are running, This is displayed in the title bar or under help, about. For example I am running 6.1.1.5.



******************************************************************
Technical explanation below, if you are curious
******************************************************************

I'll start it off with my values after 150 miles on a DME reset.

Segment (A): 1.0002
Segment (B): 0.0999
Learn. progress sens. wheel adapt.: 0.0000

One last issue remains with my rebuild. I'm getting occasional random rough running and stumbling below 680 RPM at hot idle. It's pretty random. Sometimes it will even purr along at idle for several minutes without ever hesitating. With any sort of load there is no hesitation. No codes of course, and no misfires.

I've already ohmed out my crank sensor and it is in acceptable ohm range (even when warm) 800-1000 ohms and I believe the cam position sensors are good too, as I've checked over the wiring and appropriate voltages to expect.

Short of buying an oscilloscope (which costs nearly as much a a flywheel), this is the best tool I think I have on hand in diagnosing the flywheel. (yes I did perform spring test per TSB 1360, although I did note weak springs, little resistance during test, but it did behave the way it said is a "good DMFW" in the TSB)

Here is the reason why I think that my segment and learn wheel adapt data is telling me it's the flywheel:

"When the values of segments A and B are around zero, e.g. 0.0003, adaptation is complete.

The value of learning progress must then be smaller than 0.0005.

If the value of learning progress remains at 1.0000, the flywheel is defective.

If the values of segments A and B are also at 1.000, then adaptation has not yet been performed.

In this case, perform a test drive with three deceleration phases in the speed range from 3000 to 1400 rpm." - from misfire troubleshooting guide

Of course, after 150 miles on a DME reset and countless deceleration phases, the values of segment A and B remain around 1.000, and have not changed since, and according to the guide they should be around 0. It never seems to complete adaption since the segments are around 1, but what is strange is my learning prog is 0. Before my rebuild I did read out wheel adapt and it settled on 0.0007, never reaching "good status" below 0.0005.

And if I had an o-scope I could do this test for the DMF and CKS:



And this test for the CPS and CAMs:



Thanks in advance for your time and help!

pterfloth

My laptop died otherwise I would be glad to help.

Surely someone here can help.

garrett376

Not sure if it helps, but when my flywheel went, it threw a check engine light which is how it was known as a problem. The car ran just fine, though. It would just throw a check engine light upon startup within the first 10 seconds of idling. New flywheel solved it...

Ubermensch

Logray, I'm going to throw something out there that may be completely off, but it came to mind and wanted to mention it. When I recently replaced my generator I noticed a comment at the end of the manual stating that an "adaptation" needed to be performed after completion of the work. I've done this job and countless others without ever noticing this comment in the manual. It states that after reconnecting the battery you should turn the key to "on" for at least one minute, then back to "off" for at least ten seconds prior to reading the codes. I'm assuming this is some sort of internal check that the DME is running through. If you didn't perform this process, I'm wondering whether the DME would know to run the flywheel check. From what you posted it doesn't seem like it's saying you have a bad flywheel it's staying the test was never run. Just a thought...

-Shawn

logray

Thanks for the time and ideas. I'm pretty certain this is a reference mark issue. Either with the cam or crank sensor or the flywheel itself.

I'm starting to think it could be a cam sensor issue. The cam deviation values for bank 2 are being misreported each time I reset the DME it takes many drive cycles before it "stabilizes". Initially it reads 0 degrees but then moves to 1 or 2 or even 3. Still, until enough drive cycles are complete it even will go back to 0 degrees and sometimes even blip to 1 degree at idle, but when in gear the value doesn't change. I'm wondering if this is because of an issue reading reference marks from the flywheel or crank sender. I might just bite the bullet and order up a new cam sensor. I could swap senders between banks, but that is a major pain in the *** since I have to remove the AOS.

The adaption you are speaking of I believe is for e-gas. Not cable operated. Especially considering over 150 miles of driving since the last DME reset, I'm certain I would have performed those decelerations.

I'm thinking there is an error in the documentation, either from Porsche in the misfire troubleshooting guide, or the way Durametric is reporting the data. I've opened a ticket with Durametric since I saw mention in a 2007 thread they were reporting the segment and learning wheel values incorrectly.

I threw in my spare DME and noticed the wheel adaption started at 1, and segments also at 1. After performing the three decelerations from 3000 rpm to 1400 rpm per the misfire troubleshooting guide the wheel adaption went to 0.0000, segment A 1.0001 and segment B 0.09999. Just the same as the other DME. Still, it would be nice to see someone else's data to compare with.

It's also a wonder to me that only one person across three different forums is even interested in what their segment or wheel values are. I know there are some gearheads out there! C'mon!

There are no CELs, but this issue might not even be noticeable to some, it's certainly within limits and the car is extremely drivable, just not "perfect" yet.

seanmcr6

It's funny you're sourcing this issue to your flywheel. If you remember, I had a cold start stumble...similar symptoms as your hot start stumble....for a long, long time. The dealer couldn't figure it out.

When they had to do some transmission work, I had them install my Spec 2+ clutch kit with the LWFW...and the cold start stumble disappeared.

I can check my numbers tonight when I get home as I don't have a laptop with me...

sean

logray

Thanks. After spending more time with the issue, the issue with slight rough running is present just about all the time, just a lot more noticeable once the car heats up and settles on 680 RPM. You don't really notice it by feel above 680 rpm, other than by looking at the rough running numbers from the DME.

Buy yeah, I'm definitely suspecting the flywheel, even though it was balanced during the engine balancing - perhaps it can be related to the weak DMF spring tension I noticed. Certainly the flywheel is suspect since it has nearly 78,000 miles on it. It sure tears the road up when it's in gear though. I guess who cares about idle right, it's not like I drive the car at idle? But I don't exactly want to pull up to a stop light with the car seeming like it's going to stall or stumbling all over the place randomly.

Anyhow I ordered up a cam position sensor, and if that doesn't fix the problem, then I'll probably bite the bullet and order a new DMF, but it is curious to me that the Porsche literature seems to differ from what I'm reading... either it's telling me my flywheel is out of spec or that it thinks the flywheel is OK.

Will be interesting to see what your numbers are, glad to hear the new FW resolved the stumbling.

Ahsai

Logray,

Let me know if you want numbers from an '03 c2 (not sure if '03 numbers will be as useful). I can help once I put back my mufflers on (expecting them to come back from Darin on Wed).

logray

Thanks, yeah that would be useful!

In fact, any 986/7 or 996/7.

speed rII

Ok, had the time to do this



As you can see, there is some rough running in my car allso. All thou the car was completely cold and it was 0 deg celsius outside

RR value was 10.5 when I started the car, and it was still dropping after the prtsc was taken.



Here are the fueltrims.

I have drove the car about 3650km,s after resetting the ecu.
No fault codes.

logray

Wow this is great thanks.

I think the Porsche documentation is wrong. I opened a support ticket with Durametric and they asked for more info that I will be giving them soon. I have a feeling normal would be segment A and B around 1 and learn wheel adapt below 0.0005.

Thanks again.

(p.s. more data would be good, if anyone else has the time to post their segment and wheel adapts)

mikeswift

pst2 v 24.0
996 1999 convertible
segment A 1.001
segment B 1.000

lean progregress 0.00000

thats within the normal DME setpoints.

jsoderbe

Hi, I took my stick 2001 out and tested. I got jut 1 on both, no point zero's.

I have a rough running issue, the number is parked at 21,5. How serious is that?


Johan

logray

Thanks Johan.

What is the RPM when the rough running is 21.5, and is that "rough running" or "rough running threshold"?

jsoderbe

I'm pretty sure I don't have the threshold value, which is strange considering I run 6.1.1.7.

It's idling at 840 rpm. I can see that it varies a lot, 820-850 rpm, and I can hear it wandering. The rr value for each cylinder varies from -1,5 to +1,5.

What do you think about the 1 segment A + B value? I noticed you all had decimals, I didn't....


Thanks,

Johan