Engine Management Education

[newlife]

Hi

I ordered the book, Bosch : Fuel Injection and Engine Management from Wayne but they no longer carry the book. I was wondering if anyone knew of a good book that was compreble. I ordered Wayne's book and Bentley. But since I am now a proud owner of my 2000 S I want to learn more about how exactly the Porsche engine works. Your comments are appreciated.

Rod

[mikefocke]

The little I know I learned from reading the Porsche DME manual itself where, in discussing the trouble codes, it goes into some detail in the theory of engine management and how the sensors connect and what they tell the DME.

[newlife]

Hi Mike,

Just to let you know... your advise has been proven very helpful. My Porsche is running smoother and it did pass the smog thanks to you. Mike, where can I get the Porsche DME manual you are talking about. Sounds about what I am looking for?

Rod

[paulv]

I've never seen the DME manual that Mike is speaking about, but there's some good info in these manuals:

Planet-9 - Downloads - Misc / Other

Look at the After Sales Training pdf's. Engine Mgt Systems and Advanced Engine Mgt Systems both have some good info.

Regards,

paul...

[newlife]

Wow,

thanks Paul..

Rod

[thstone]

Book is available at Amazon.com:

Amazon.com: Bosch Fuel Injection and Engine Management: How to Understand, Service and Modify (9780837603001): Charles O. Probst: Books

I have read this book and its very helpful in understanding the premises of DME operation.

[JFP in PA]

Originally Posted by mikefocke

The little I know I learned from reading the Porsche DME manual itself where, in discussing the trouble codes, it goes into some detail in the theory of engine management and how the sensors connect and what they tell the DME.

The diagnostic manual I think Mike is refering to is part of the 13 volume set of original print service manuals for the Boxsters. Two volumes, Group "O", volumes 1 & 2 cover the DME diagnostics, and contain pretty much the same information concerning fuel adaptation values, ranges and limits; as well as much, much more.........

And before someone asks, the manuals are no longer in print (originally cost $2,300 without the seperate $1,800 OBD II diagnostics manual) and very hard to find.

[newlife]

Thanks JFP,

I appreciate the post.

Rod

[newlife]

Originally Posted by thstone

Book is available at Amazon.com:

Amazon.com: Bosch Fuel Injection and Engine Management: How to Understand, Service and Modify (9780837603001): Charles O. Probst: Books

I have read this book and its very helpful in understanding the premises of DME operation.

Thank you for the tip... just ordered it.

Rod

[Dale_K]

Originally Posted by thstone

Book is available at Amazon.com:

Amazon.com: Bosch Fuel Injection and Engine Management: How to Understand, Service and Modify (9780837603001): Charles O. Probst: Books

I have read this book and its very helpful in understanding the premises of DME operation.

I'm willing to spend the money but I need to know whether the book translates the Porsche/Durametric terminology such as "loss adaptation RKAT" into something I can understand. The specific issue I had, which turned out to be a bad MAF sensor, was only solved when someone could interpret the Durametric values I posted. Does the book help in this regard?

[newlife]

Originally Posted by Dale_K

I'm willing to spend the money but I need to know whether the book translates the Porsche/Durametric terminology such as "loss adaptation RKAT" into something I can understand. The specific issue I had, which turned out to be a bad MAF sensor, was only solved when someone could interpret the Durametric values I posted. Does the book help in this regard?

Dale,

I ordered the book yesterday, I will check for you once I recieve it.

Rod

[JFP in PA]

Originally Posted by Dale_K

I'm willing to spend the money but I need to know whether the book translates the Porsche/Durametric terminology such as "loss adaptation RKAT" into something I can understand. The specific issue I had, which turned out to be a bad MAF sensor, was only solved when someone could interpret the Durametric values I posted. Does the book help in this regard?

Dale, we all feel your pain when it comes to "Porsche speak". I’ve been around these things for a long time, and never cease to be amazed at some of the terminology you find in English versions of the factory service literature and technical bulletins; while the word usage is often technically correct, it is often undecipherable; and abbreviations are typically from the German so they typically make little, if any, sense at best. So camshaft timing becomes “allocations”, and then we find the term "tempostat" (Porsche speak for cruise control) we are left scratching our heads.

[harryrcb]

Originally Posted by JFP in PA

Dale, we all feel your pain when it comes to "Porsche speak". I’ve been around these things for a long time, and never cease to be amazed at some of the terminology you find in English versions of the factory service literature and technical bulletins; while the word usage is often technically correct, it is often undecipherable; and abbreviations are typically from the German so they typically make little, if any, sense at best. So camshaft timing becomes “allocations”, and then we find the term "tempostat" (Porsche speak for cruise control) we are left scratching our heads.

you are so right, I speak fluid german and I don't get those translations. I think they might have had a chinese guy translate the german to english

[thstone]

Originally Posted by Dale_K

I'm willing to spend the money but I need to know whether the book translates the Porsche/Durametric terminology such as "loss adaptation RKAT" into something I can understand. The specific issue I had, which turned out to be a bad MAF sensor, was only solved when someone could interpret the Durametric values I posted. Does the book help in this regard?

This book is a somewhat generic explanation of various Bosche fuel injection systems. It is NOT a Porsche specific manual for Motronic fuel injection. However, after reading the book I can mostly decode the Porshe specific Durametric and error codes into something that makes sense (but I also have a degree and 20+ years experience in control systems engineering so I might have a bit of a headstart).

Don't get me wrong - this is a very good book and will give you a good understanding of digital engine control, feedback loops, various sensor inputs and how the DME adjusts for various conditions. You'll need to know this stuff if you want to understand more specifically how a Porsche DME works but the Porsche specific stuff isn't in this book.

To answer your question directly, I believe that RKAT = Adaptation in range close to idle (Bank1)

Simply put, this is one of several adaptation values that the DME has calculated and stored to "trim" the air/fuel mix in order to maintain performance and emissions. This adaptation process is discussed in the book, but the exact terms (e.g. RKAT) are not in the book.

[paulv]

RKAT (b1 or b2) = Long Term Fuel Trim (banks b1 or b2) at Idle. MAF needs to show 12-32kg/hr. Adaptation range is 0.00 to +/- 3.50 mg/stroke (mg of fuel per intake downstroke).

FRAU (b1 or b2) = Long Term Fuel Trim (banks b1 or b2) under load - lower range. MAF needs to show 32-220kg/hr. Range is 0.0 to +/- 35%. The tank vent valve needs to be closed when testing this.

FRAO (b1 or b2) = Long Term Fuel Trim (banks b1 or b2) under load - upper range. MAF needs to show 220+kg/hr. Range is 0.0 to +/- 35%. The tank vent valve needs to be closed when testing this.

HTH.

Regards,
paul...

[newlife]

Originally Posted by thstone

This book is a somewhat generic explanation of various Bosche fuel injection systems. It is NOT a Porsche specific manual for Motronic fuel injection. However, after reading the book I can mostly decode the Porshe specific Durametric and error codes into something that makes sense (but I also have a degree and 20+ years experience in control systems engineering so I might have a bit of a headstart).

Don't get me wrong - this is a very good book and will give you a good understanding of digital engine control, feedback loops, various sensor inputs and how the DME adjusts for various conditions. You'll need to know this stuff if you want to understand more specifically how a Porsche DME works but the Porsche specific stuff isn't in this book.

To answer your question directly, I believe that RKAT = Adaptation in range close to idle (Bank1)

Simply put, this is one of several adaptation values that the DME has calculated and stored to "trim" the air/fuel mix in order to maintain performance and emissions. This adaptation process is discussed in the book, but the exact terms (e.g. RKAT) are not in the book.

Wow ! Awesome relply, thank you.

Rod

[Dale_K]

The stuff over at Planet 9 in the files section looks like interesting reading but I'm not able to download any of it, even after I registered on their system. I get a message that says it's not shared to me. Anybody else run into this, or how to fix it? Is it for paid members?

[paulv]

Originally Posted by Dale_K

The stuff over at Planet 9 in the files section looks like interesting reading but I'm not able to download any of it, even after I registered on their system. I get a message that says it's not shared to me. Anybody else run into this, or how to fix it? Is it for paid members?

I just thought of this -- maybe new members need to do an initial posting before they're allowed to download stuff. I pulled those files down a couple of years ago, and I don't remember exactly the procedure, sorry.....

Regards,
paul...