Rennlist Discussion Forums   classifieds | membership | rennlist | photo album    
sponsors | upload photo | chat    
 
Go Back   Rennlist Discussion Forums > 924/944/951/968 Model Specific Technical Forums > 944 Turbo and Turbo-S Forum
Sign in using an external account
Register Forgot Password?
Search

Reply
 
Thread Tools Search this Thread
Old 03-19-2005, 02:19 AM   #31
evil 944t
Addict
Rennlist Member
 
evil 944t's Avatar
 
Join Date: Feb 2003
Location: Chicago
Posts: 3,526
Default

Quote:
Originally Posted by Lorenfb
A good text for many to read is the "Bosch Fuel Injection & Engine Management"
by Charles Probst (SAE member). Also, the Bosch "Automotive Handbook" (3rd edition)
is very informative. For those interested in more recent Porsche technology, the Porsche
DME 7.2 Manual - OBD II (WKD 483921) is another good read.

For those that are DIY types, get an old DME unit and apply power
to pins 18 & 35, ground to pin 17. Then use a sine wave signal generator
to apply a speed signal to pins 8 & 27. Use a differentiated square wave applied
to pins 25 & 26 (ref signal), and you'll have a functioning DME unit to "play" with.

Use this approach to fix your own DME problems.

For those software types, "read" the EPROM as a binary hex file
and save it on your P.C. Then use the MS DOS DeBug program and
you can disassemble (list the 8051 code) it and figure out what
the DME is doing in your 944.

No real mystery to the 944 DME, it's very very simple technology you
might find in a high school electronics class. So let's not over rate
those that appear to be knowledgeable about the DME operation.
The 996's technololgy with OBDII and the immoblizer gets a little
more involved.

Bottomline: The 944 DME design is over 20 years old now and many
(like lots) have "hacked" it. So there ain't any real 944 DME gurus,
just some who think they are, as is obvious from this forum.
wow, your irrogant. Makes me want to use your services.
To remove this ad, register today or login if you already are registered!

__________________
89 944 Turbo S
86 944t Track only
01 996tt
evil 944t is offline   Reply With Quote
Old 03-19-2005, 02:31 AM   #32
Lorenfb
Super User
 
Lorenfb's Avatar
 
Join Date: May 2003
Location: Manhattan Beach, CA
Posts: 3,014
Default

"wow, your irrogant. Makes me want to use your services." - evil 944t -

Whatever!
Lorenfb is offline   Reply With Quote
Old 03-19-2005, 02:34 AM   #33
evil 944t
Addict
Rennlist Member
 
evil 944t's Avatar
 
Join Date: Feb 2003
Location: Chicago
Posts: 3,526
Default

Why don't you just use your OHM meter and figure out how to use your "" button.
__________________
89 944 Turbo S
86 944t Track only
01 996tt
evil 944t is offline   Reply With Quote
Old 03-19-2005, 02:37 AM   #34
NZ951
Super User
 
NZ951's Avatar
 
Join Date: Apr 2003
Location: New Zealand massive
Posts: 13,763
Default

Quote:
Originally Posted by Lorenfb
"wow, your irrogant. Makes me want to use your services." - evil 944t -

Whatever!

Dont worry about him Loren, some people just like running other people down. Thanks for being a site sponsor!
NZ951 is offline   Reply With Quote
Old 03-19-2005, 02:53 AM   #35
TT
User
 
Join Date: Jun 2001
Location: Huntingtown, MD
Posts: 363
Default

Quote:
Then use the MS DOS DeBug program and you can disassemble (list the 8051 code) it and figure out what the DME is doing in your 944.
Lorenfb. Have you successfully tried to load and disassemble a Motronic image this way?

Code:
debug tmp.hex
-u 0000
1382:0000 0202          ADD     AL,[BP+SI]
1382:0002 4E            DEC     SI
1382:0003 C28B21        RET     218B
1382:0006 F0            LOCK
1382:0007 FFFF          ???     DI
1382:0009 FFFF          ???     DI
1382:000B D290C20A      RCL     BYTE PTR [BX+SI+0AC2],CL
MSDOS debug is an 8086 disassembler/debugging tool, not an 8051 tool.

The first instruction 02024E is 'ljmp 024Eh', not an add op-code.
TT is offline   Reply With Quote
Old 03-19-2005, 09:44 AM   #36
awilson40
User
 
awilson40's Avatar
 
Join Date: Jun 2001
Location: Winterville, NC
Posts: 1,688
Default

Quote:
Originally Posted by Lorenfb
944 Turbo

This uses an idle switch & WOT switch and a TPS combined into one unit.
The outputs from these go to the DME pins 2 & 3, respectively. The TPS
outputs go to the KLR pins 21, 22, 23.
Bottomline: The DME has a switch inputs element and the KLR has a true TPS input,
i.e. a varying voltage input
Now I know this is wrong.
There is only an idle switch and NO WOT switch in the 944 turbo TPS(Throttle position sensor)
The WOT Signal is derived from an output from the KLR and sent to the DME to "signal" Full throttle.
On a side note... I have wondered if the "click at idle" adjustment is really the best way to set. It really depends on whether the KLR is using the throttle position sensor as a true indicator of throttle plate position OR, as I suspect, only an indication of the 'rate of change' to 'Drive' a WOT signal for the DME.
On cars where the TPS signal is used in fuel/timing calculations then idle position is set by adjusting the sensor to a given voltage at idle.

But the 944 TURBO only has an idle switch and a Pot , No WOT switch.

TT...be careful how much info you give

Last edited by awilson40; 03-19-2005 at 02:57 PM.
awilson40 is offline   Reply With Quote
Old 03-19-2005, 10:44 AM   #37
hosrom_951
UAE Rennlist Ambassador
Rennlist Member
 
hosrom_951's Avatar
 
Join Date: Jan 2004
Location: UAE & Germany
Posts: 9,142
Send a message via ICQ to hosrom_951 Send a message via MSN to hosrom_951
Default

Andrew: I don't want to start anything and don't quote me just yet, but i do recall seeing the 951 throttle switch operation. If memory serves correctly, it has idle, cruise and WOT switches.

Again, i am not sure 100% if it is for the 951 or the NA models, i will post it when i find it.

__________________
Hussam Jamil <- Why is my name here?
RLM#:040430-3502
'86 944 Turbo-German Spec (In Dubai)
'96 BMW 328is-Japan Spec (Sold)
'06 BMW 325i-Gulf Spec (In Dubai)
'12 BMW 530i - German Spec (In Germany)
'13 BMW 530 - Gulf Spec (In Dubai)
hosrom_951 is offline   Reply With Quote
Old 03-19-2005, 11:10 AM   #38
hosrom_951
UAE Rennlist Ambassador
Rennlist Member
 
hosrom_951's Avatar
 
Join Date: Jan 2004
Location: UAE & Germany
Posts: 9,142
Send a message via ICQ to hosrom_951 Send a message via MSN to hosrom_951
Default

Here:

(courtesy of Bruce@arnnworx)
Click the image to open in full size.
__________________
Hussam Jamil <- Why is my name here?
RLM#:040430-3502
'86 944 Turbo-German Spec (In Dubai)
'96 BMW 328is-Japan Spec (Sold)
'06 BMW 325i-Gulf Spec (In Dubai)
'12 BMW 530i - German Spec (In Germany)
'13 BMW 530 - Gulf Spec (In Dubai)
hosrom_951 is offline   Reply With Quote
Old 03-19-2005, 01:07 PM   #39
Bri Bro
Addict
Rennlist Member

 
Join Date: Feb 2002
Posts: 5,384
Default

Quote:
Originally Posted by TT
Lorenfb. Have you successfully tried to load and disassemble a Motronic image this way?

Code:
debug tmp.hex
-u 0000
1382:0000 0202          ADD     AL,[BP+SI]
1382:0002 4E            DEC     SI
1382:0003 C28B21        RET     218B
1382:0006 F0            LOCK
1382:0007 FFFF          ???     DI
1382:0009 FFFF          ???     DI
1382:000B D290C20A      RCL     BYTE PTR [BX+SI+0AC2],CL
MSDOS debug is an 8086 disassembler/debugging tool, not an 8051 tool.

The first instruction 02024E is 'ljmp 024Eh', not an add op-code.
TT is dead on, the 8751 op codes and internal structure are entirely different then the 8086. The 8751 is an 8 bit controller with built in I/O, Ram, Serial Ports,Timers and ROM. The 8086 is a 16 bit processor and doesn’t have support functions built in like the 8751 does. And as a preemptive defense, I have built/programmed the 8751 on many occasions in the past. This series of micro processor (MSC51) is still being used, but is getting very dated. Anyone want to pore through hundreds of pages of spec sheets comparing the two, here is the link.
http://www.datasheetarchive.com/datasheet/pdf/4332.html

And after all is said and done, the TPS does click. I would go nut if everybody started calling components by the Porsche manual names. The manual are translated from German and some of the names are just nuts!

Last edited by Bri Bro; 03-19-2005 at 04:32 PM.
Bri Bro is offline   Reply With Quote
Old 03-19-2005, 01:55 PM   #40
Lorenfb
Super User
 
Lorenfb's Avatar
 
Join Date: May 2003
Location: Manhattan Beach, CA
Posts: 3,014
Default

"Andrew: I don't want to start anything and don't quote me just yet, but i do recall seeing the 951 throttle switch operation. If memory serves correctly, it has idle, cruise and WOT switches." - hosrom_951 -

He's correct.

And for the others, stop guessing! Please read page 19 of the 944 Turbo manual (WKD 453 920).

MS DOS DeBug obviously is NOT the most appropriate assembler to
use, but it is simple and allows code mods, e.g. timing & fuel, and a
BASIC overview of the u-code of a DME.
Lorenfb is offline   Reply With Quote
Old 03-19-2005, 03:13 PM   #41
awilson40
User
 
awilson40's Avatar
 
Join Date: Jun 2001
Location: Winterville, NC
Posts: 1,688
Default

From the factory prints.
The dual switch set up is from an NA including the S2

The single switch with a variable resistor (TPS)
is from a turbo.
awilson40 is offline   Reply With Quote
Old 03-19-2005, 03:19 PM   #42
TT
User
 
Join Date: Jun 2001
Location: Huntingtown, MD
Posts: 363
Default

Quote:
TT is dead one.
I hope you meant dead on.
TT is offline   Reply With Quote
Old 03-19-2005, 04:25 PM   #43
hosrom_951
UAE Rennlist Ambassador
Rennlist Member
 
hosrom_951's Avatar
 
Join Date: Jan 2004
Location: UAE & Germany
Posts: 9,142
Send a message via ICQ to hosrom_951 Send a message via MSN to hosrom_951
Default

Andrew: I am no wiz kid, nor familiar with the details on the TPS/Bosch systems......but take a look at the TPS that Bruce dis-assembled, compare that to the diagram:

http://www.arnnworx.com/tps-repair.htm

I don't see them similar
__________________
Hussam Jamil <- Why is my name here?
RLM#:040430-3502
'86 944 Turbo-German Spec (In Dubai)
'96 BMW 328is-Japan Spec (Sold)
'06 BMW 325i-Gulf Spec (In Dubai)
'12 BMW 530i - German Spec (In Germany)
'13 BMW 530 - Gulf Spec (In Dubai)
hosrom_951 is offline   Reply With Quote
Old 03-19-2005, 04:33 PM   #44
Bri Bro
Addict
Rennlist Member

 
Join Date: Feb 2002
Posts: 5,384
Default

Oops, corrected...thanks TT
Bri Bro is offline   Reply With Quote
Old 03-19-2005, 04:52 PM   #45
awilson40
User
 
awilson40's Avatar
 
Join Date: Jun 2001
Location: Winterville, NC
Posts: 1,688
Default

The resistance values stated are the 'range' from idle to WFO...not a 'switching point'
When you check a TPS with an analog ohm meter you will , or should, get a smooth resistance
increase from idle to full open that falls in the range of the factory specs.
This does not mean that there is a full throttle 'switch' or point...just that a 'good' TPS will fall within this range.
Other than that, the diagrams are simular...I just think you are interpreting the info a little wrong.

BTW, I'm no expert on Bosch...just a military trained avionics tech and an automotive mfg engineer.
awilson40 is offline   Reply With Quote
Old 03-19-2005, 04:52 PM
Rennlist



Paid Advertisement
Reply

Tags
2003, 453, 912, 920, 944, adjustment, element, idle, location, manual, porsche, specs, switch, tps, turbo, wkd

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -3. The time now is 05:21 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.1
Copyright © 1998 - 2007 Rennlist.com

Advertise on Rennlist - Privacy Statement - Terms of Service - Jobs