Pages: 1 [2]
Author Topic: Boxster 986 low power  (Read 12261 times)
vwaudiguy
Hero Member
*****

Karma: +53/-37
Offline Offline

Posts: 2024



« Reply #15 on: April 16, 2017, 10:24:46 AM »

Being NA, I suppose your options are throttle plate position, cam position, and ignition timing. Do you have a properly running example to compare to? Monitor AFR with an external wideband if need be. Do you have any logs to share? No faults in the TCU? Could be the mismatch between ecu's is interfering with the tip function like you mentioned.
« Last Edit: April 16, 2017, 10:28:02 AM by vwaudiguy » Logged

"If you have a chinese turbo, that you are worried is going to blow up when you floor it, then LOL."
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #16 on: April 17, 2017, 01:59:46 AM »

Thanks a lot for your suggestions.

Throttle plate is moving from a few percents to 99% when I try to accelerate hard (monitored with a tester). But between about 60% and 99% you cannot feel any difference in acceleration, only the sound of the engine changes from supplemental air... So I think that the throttle position is not the issue.

Cam position may be a problem, but monitored seems ok and the software from ME7 is very sensible at cam problems and gives DTC at every slight mismatch. There is no DTC...

Ignition timing is a problem. No matter how much acceleration I try, it never goes over 20 degrees. Also the torque never exceeds 50%. I don't know if the torque is limited by ignition timing or the ignition timing is low because of a limitation in torque. I try to raise gradually the ignition timing maps until over 20%. There is no modification in engine functionality at all... I did not fully understand the procedure of disabling torque monitor in ME7 with winols, so I did not took my chances to play with it.

I don't have a comparable car to test. And the combination of engine and ECU I have is not installed on any Porsche...

I don't have a wideband monitor for AFR. I consider buying one. But at the official annual emission test I made these days, everything seems normal.

The problem of mismatch between engine ECU and the tip ECU is plausible. My guess is that the engine ECU is understanding to keep low torque like when it is changing gears. But I really don't know how to investigate, I have no idea where are the maps and switches in winols to try to test disabling the limiting functions of the tip over engine. There is no DTC on the tip also.

Thanks again for support.

« Last Edit: April 17, 2017, 05:29:27 AM by videovox » Logged
mister t
Sr. Member
****

Karma: +74/-18
Offline Offline

Posts: 343


« Reply #17 on: April 19, 2017, 06:10:16 PM »

have you asked sedox?

BTW, as others have noted, this is a pretty rudimentary file, I hope you didn't pay more than $150-200 for it....
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #18 on: April 20, 2017, 01:17:27 AM »

Hello and thanks for reply.

Sedox tried more than one version of file. But no matter how much they tried to change values in maps, the power of the engine remained pretty the same.They said, like I also supposed, that something is limiting the engine at torque 50% and/or timing 20grd. But they could not tell me what...
Logged
nubcake
Sr. Member
****

Karma: +53/-4
Offline Offline

Posts: 401


« Reply #19 on: April 20, 2017, 02:44:17 PM »

I'm not sure how to approach this without proper logging. Sad
When you say "torque limited at 50%" - where did you see that?
Generic OBD PID?
Logged
DRD
Newbie
*

Karma: +1/-0
Offline Offline

Posts: 5


« Reply #20 on: April 21, 2017, 01:15:42 PM »

I got experience with these engines.
You need to look ant the timming and afr. durametric will tell you what yo need to know.
Timming usally runs around 6 degrres at idle, and it will  40 degress off idle til cruising, up to abut 40 load, when you get into it, it will pull the timming back to 17 to 25 degrees, depending how hot it is outside. The varicam plus+ will switch off the low lobe to the high depending on the load, the cams advance around 1800 rpm, and it will  pull the cam adavance out at 5300rpm. Afrs run 14.7 at idle and cruise, and wide open they are tunned to 12.5, it run best at 12.8- 13 afr. The ecu runs closed loop also all the time. 
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #21 on: April 22, 2017, 02:24:21 PM »

Hello DRD, nubcake and all others,
I managed to get some logs from durametric. I attach two logs, taken on a trip in town. These logs are different, as I cannot log a lot of parameters at once. Hope to be of help, if anybody needs different parameters please let me know, I will try to find them with durametric. I could not measure afr, as it is not an option of durametric for this ecu.
I was wrong about the ignition angle, it goes well above 20 grd. But the torque is very low and I think the air is low also.

Please help me with a suggestion if you can.
Logged
mister t
Sr. Member
****

Karma: +74/-18
Offline Offline

Posts: 343


« Reply #22 on: April 22, 2017, 05:59:42 PM »

I would recommend posting your logs with Megalogviewer (from EFIanalytics.com) It's only about $70 and it's the best money you'll ever spend

Here are scatterplots of your first and second logs
« Last Edit: April 22, 2017, 06:01:47 PM by mister t » Logged
DRD
Newbie
*

Karma: +1/-0
Offline Offline

Posts: 5


« Reply #23 on: April 22, 2017, 08:39:55 PM »

From what I can see, you not getting the engine torque, for 99% percent pedal, throttle plate is plate opened 99%, engine torque is half, 50% at 4800 rpms, should be 90-95%. Some cars had a psm, 996-997 had it,Porsche stability magagment, that control torque map. Take a look at the ecu, and see id there are inputs for a psm signal on it.
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #24 on: April 23, 2017, 03:50:33 AM »

From what I can see, you not getting the engine torque, for 99% percent pedal, throttle plate is plate opened 99%, engine torque is half, 50% at 4800 rpms, should be 90-95%. Some cars had a psm, 996-997 had it,Porsche stability magagment, that control torque map. Take a look at the ecu, and see id there are inputs for a psm signal on it.

Thanks for your reply.

Yes, I have PSM. It is connected with the engine ECU only through CAN, no special wire connection. I drove today with PSM disabled through dashboard switch, but there was no difference. So I think PSM is not the problem.
As I know for this ECU, torque is directly related to air mass. Do you have some values of the air mass from a equivalent engine to compare?

I would recommend posting your logs with Megalogviewer (from EFIanalytics.com) It's only about $70 and it's the best money you'll ever spend

Here are scatterplots of your first and second logs


Thanks for suggestion. I will consider buying this software next week.
Logged
DRD
Newbie
*

Karma: +1/-0
Offline Offline

Posts: 5


« Reply #25 on: April 23, 2017, 07:30:52 AM »

I will data log some maf valves you, and post them. I know off hand, it idles around 16 grams , and have seen 100+ grams when on the throttle.
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #26 on: April 23, 2017, 02:26:42 PM »

Thanks. Important informations...
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #27 on: April 25, 2017, 11:48:04 AM »

Hello all,

I got new logs for my car. One is AFR - Lambda, and one is camshafts.

Please tell me if there si something not ok with these...

Thanks.
Logged
videovox
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 26


WWW
« Reply #28 on: May 12, 2017, 12:00:33 PM »

Hello all,

After a lot of work I finally sorted out the low power problem.

There was not enough air for the engine. And the cause was that the Variocam Plus was not working well, the valve lift is not enabled in the software version I have. Now I am trying to find a method of enabling it.
I started a new topic for this at
http://nefariousmotorsports.com/forum/index.php?topic=12564.0title=

If someone can help I thank him in advance!
Logged
Pages: 1 [2]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.021 seconds with 17 queries. (Pretty URLs adds 0.001s, 0q)