Ultimate MFI resources thread

[David E. Clark]

The idea came up in another post to gather all the MFI related resource information (with links) in one post. The Bosch Mechanical Fuel Injection Compilation by John Hunt is a GREAT start but lets try to get it all in one place!

I'll start with everything in my collection with links included where I have them. I have also included identifying information for other stuff that I have collected (without links). Lets get all the information in this post. It will make a great resource. Here's my stuff:

1. Factory Workshop Manual, Volume I, pages SF 11 through SF 42. These pages give a description of the system along with useful schematic diagrams. Of particular help is the three page "Fuel Injection Trouble Shooting Chart." Buy the Factory Workshop Manual here. Expensive but worth it!

Fuel Injection Troubleshooting Chart pages SF28-SF30. Posted in this thread below.

2. Factory Workshop Manual, 1972 Supplement, volume 2, pages 1-1/1 through 1-2/3; 3.1 1/1 through 1/4. Contains useful information about adjusting the injection pump with an emission tester and adjusting the micro switch on the 1972 and 1973 models. Buy the Factory Workshop Manual Supplement here. Expensive but worth it!

Adjusting Fuel Injection Pump with Emission Tester, page 3.1 1/1. Posted in this thread below.
Adjusting MFI Engine Idle, pages 3.1 1/2 - 3.1 1/3. Posted in this thread below.
Adjusting MFI Micro Switch - Beginning with 1972 Models, page 3.1 1/4. Posted in this thread below.
Factory recommended part load co2 settings. Posted in this thread below.
Explanation of why MFI cars run rich at idle but get leaner when they are driven hard. Posted in this thread below.

3. Porsche Technical Specifications - 72, 73 Models Fuel Injection System pages 54-55. Posted in this thread below. Buy the Factory Specifications Books here.

4. Mechanical Fuel Injection, Check Measure Adjust. The Bible! 47 pages of must have material for any MFI owner.

Differences in Check, Measure Adjust Manuals.

Porsche Product Information Circular P250 stating that the MFI protractors described in the factory workshop manual and CMA are no longer required to set proper correlation. Posted in this thread below.

5. Bosch MFI Repair Instructions. Just follow the link from the homepage to this article. Detailed repair instructions including useful torque specs.

6. Bosch MFI Repair Instructions, supplement 2. Just follow the link from the homepage to this article.

7. Fuel Injector Maintenance. How to maintain mechanical fuel injectors -- Just like it sounds!

8. Mechanical Fuel Injection by Leslie Rice. Wonderful overview of the MFI system from a guy that really understands it. Great advice like "NEVER DEVIATE" from the sequence outlined in Check, Measure and Adjust.

9. Adjustments to the MFI pump for timing and mixture by Leslie Rice. Includes advice on making adjustments to the MFI pump, timing the MFI pump and inspecting the MFI timing belt. Also describes useful tools.

10. MFI diagrams and cutaways. Great illustrations including exploding diagrams in case you ever take the thing apart!

BOSCH MECHANICAL FUEL INJECTION PUMP ASSEMBLY SECTION
BOSCH MECHANICAL FUEL INJECTION REGULATOR SECTION
THROTTLE BODY LINKAGES
THERMOSTAT DIAGRAM
FUEL SYSTEM DIAGRAM
MFI SYSTEM DIAGRAM
MFI FILTER DIAGRAM
1969 MFI SYSTEM EXPLODING DIAGRAM

EXPLODING DIAGRAMS FOR 1972-1973 MFI SYSTEM. Posted in this thread below.

ELECTRICAL WIRING DIAGRAM FOR EARLY MFI CARS. These electrical wiring diagrams were converted by Derek Murray. Electrical diagrams for the early cars are also posted on the Rennlist website here.

11. Group 21 Fuel Injection System exploding diagrams from Parts Manual. Choose "Porsche Original PDF Parts catalogue" from the left hand column and your year and model from the right column. More valuable exploding diagrams.

12. Excellence Magazine technical notes II, pages 60-66.

13. RPM Transducer/Speed Switch for Bosch MFI diagram. Posted in this thread below.

14. Throttle body linkages diagram from "Porsche Service Repair Handbook" Clymer Publications (1976) page 210. This same diagram is on page SF22 of the Factory Workshop Manual (April 1972 edition).

15. Autosolve Mechanical Fuel Injection article. Really deals with the Bosch K-Jetronic system but still a pretty good read.

16. Project 30, page 91, Mechanical Fuel Injection Troubleshooting and Adjustment, 101 Projects for your Porsche 911 . Buy the book here.

17. American Bosch Fuel Injections, Equipment and Service (74 pages) (1972). Covers MFI for Diesel engines but has good background information.

18. Replacing the MFI Fuel Filter from Porsche 911T/E/S Model '73 Driver's Manual page 62. Posted in this thread below. Buy the Driver's Manual here.

19. Porsche Panorama Magazine has a decent overview article called "Porsche Mechanical Fuel Injection Systems" in the April 1999 issue at page 30.

20. "Up-Fixin der Porsche" has various somewhat helpful bits on Mechanical Fuel Injection at:

"Mechanical Fuel Injection" in Volume 5, page 146. Compares MFI to CIS and carburetors.
"Mechanical Injection" in Volume 6, page 31. Short discussion of gas in oil problem with some MFI systems.
"Mechanical Injection Pump Rebuilds" in Volume 7, page 120. Idle adjustment on MFI cars.
"Mechanical Injection Pump Rebuilds" in Volume 7, page 121. Rebuilders addresses current as on July 1986. More recent information about MFI rebuilders can be found here.
"Mechanical Injection" in Volume 8, page 125.
"Mechanical Injection 911T" in Volume 8, page 125.

The "Haynes", "Clymer", "InterEurope", "Chiltons", and "Autobooks", manuals only have VERY general information about Mechanical Fuel Injection. I also have a "Drake" Porsche 911 Workshop Manual but it really covers the 356 (go figure), so it's no help.

21. Of course, the search function on Pelican Parts is your best friend!

Because of space limitations, MFI Technical Message Board Postings are listed and described in this thread:

MFI Message Board Index.

Please add your links and resources to this page and make it a better resource for all of us

[David E. Clark]

I included some suggestions for making the list easier to use. I've also included a direct link to the Check, Measure, Adjust manual. Now you have NO EXCUSE for not adding resources to this list! We MFI guys have to stick together!!

[David E. Clark]

RPM Transducer/Speed Switch for Bosch MFI diagram. (#15 in list above). Posted here for educational purposes.

Credit for this goes to:
Early S Man
and/or
Mike Gillies of Brisbane, Australia

[David E. Clark]

Fuel Injection System Specifications (1972-1973). (#3 in the list above). Posted here for educational purposes.

[David E. Clark]

Replacing the MFI Fuel Filter. (#22 in the list above). Posted here for educational purposes.


© Dr. Ing. h.c. F. Porsche A.G.

[pwd72s]

Bravo, David! Great posting work! Thanks!

[David E. Clark]

Adjusting MFI Engine Idle (From # 2 in the list above). Posted here for educational purposes.

PAGE 3.1-1/2:

PAGE 3.1-1/3:

© Dr. Ing. h.c. F. Porsche A.G.

Originally posted by Tyson Schmidt
It takes about 6 clicks on the idle screw to have the same effect as one click on the main rack.

The idle screw only acts on the first stage spring on the rpm weights. So it really only affects the mixture at low rpm.

[724doorE]

Good Grief! Nice lot of info all in one place!

Thanks, maybe this time I'll keep track of it all!

Awsome thread with lots of info. Thanks for sharing!

[David E. Clark]

Originally posted by 724doorE
Good Grief! Nice lot of info all in one place!

That's the plan! Please help us out by posting any MFI information not listed above. If anyone has any links, just post them here and I'll edit them into the list at the top so that all the links are in one place. Information that would be particularly helpful is:

- Any Porsche Service School MFI publication(s) (I don't know if these exist).

- Any Factory MFI materials I missed.

- Any "How To" MFI articles from local Porsche Club publications.

- Any "How To" MFI articles from the major Porsche publications (911 and Porsche World, Excellence, Panorama, Christophorus, Total 911, GT Purely Porsche, etc).

- Copies of the "coming soon" articles not yet on our sponsor's page: (1) Bosch MFI Storage instructions , (2) Bosch MFI Pump Test Instructions, (3) Fuel System (incl. MFI) Maintenance, (4) Tuning Instructions (I would really love to see this); and (5) Mercedes MFI Adjustment Instructions.

- Helpful MFI tuning or calibration information from industry mechanics manuals.

- Additional suggestions for tools or techniques. For example, I've read that several folks have made the protractors. If you could share the technique (maybe the tool diagrams) and where you got the materials that would be helpful.

- Any links to MFI materials online in websites that are not listed above. (perhaps deep links in private sites that you'd be willing to share).

- Finally, if anyone has indexed the MFI threads from this site, posting that would be GREAT!

I'll keep posting what I have that I cannot link to and I will continue to update the top list with any links that are sent to me. Please help out this project by posting your materials and links as well.

[David E. Clark]

Adjusting Fuel Injection Pump with Emission Tester (From # 2 in the list above). Posted here for educational purposes.

PAGE 3.1-1/1:

Image is two posts below.

Thanks Peter!

[evren]

looks like there is a blank space before the file name?

[POKDUB]

Located and inserted pic 4 U.
I think there is a problem with the size/format of the file name.

Adjusting+Fuel+Injection+Pump+with+Emission+Tester

[David E. Clark]

Lots of new links and edits added to the compilation at the top of this thread. Check it out!

Don't forget to add your resources and links -- for example, point out what MFI threads you found particularly useful -- so that we can enhance the value of this resource for everyone.

I'll make sure all new material is added to the compilation at the top of this thread so it's all in one place!

[derek murray]

David - the electrical schematics for MFI equipped cars may be useful... and thanks for putting this thread together.

early wiring diagram - download here

[Grady Clay]

There are three different MFI circuits:
1969 only
1970 only
’71-‘73

I’m working to convert each from wiring schematics to current flow diagrams. I have the diagrams roughed in and am collecting images of all the devices, connections and connectors. I’m using the connector nomenclature as in a ’74 current flow diagram. I’m going to identify each harness and link every wire to the harness it is in.

Does someone know of a suitable freeware wiring diagram program or can mail me a copy?

The diagrams in this series that I have are:
SL35 “Wiring Diagrams Type 911E, 911S” (1969)
NE35 “Electric Wiring Diagram Type 911T, 911E, 911S.” (1970)
SL37 “Electric wiring diagram (Part I) Type 911T, 911E, 911S, Model 71.”
SL39 “Electric wiring diagram (Part II) Type 911T, 911E, 911S, Model 71.”
0.1-2/1 “Electric wiring diagram (Part I) Type 911T, 911E, 911S, Model 72.”
0.1-2/3 “Electric wiring diagram (Part II) Type 911T, 911E, 911S, Model 72.”
0.1-2/5 “Electric wiring diagram (Part I) Type 911T, 911E, 911S, Carrera 2.7, Model 73.”
0.1-2/5 “Electric wiring diagram (Part II) Type 911T, 911E, 911S, Carrera 2.7, Model 73.”

There are two (’72) supplementary diagrams 0.1-2/9 for front and rear fog lights and 0.1-2/11 for electric windows.

There is also 0.1-2/13 “Electric wiring diagram (Part I) Type 911T with CIS, Model 73” and 0.1-2/15 “Electric wiring diagram (Part II) Type 911T with CIS, Model 73.”

’74 is the first year for Current flow diagrams.
I haven’t researched ’74 and later for MFI.
My diagrams are mostly for USA 911s.

Best,
Grady

[David E. Clark]

Adjusting Micro Switch - Beginning with 1972 models (From # 2 in the list above). Posted here for educational purposes.

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© Dr. Ing. h.c. F. Porsche A.G.

[POKDUB]

Grady,

This one is simple and free

www.electronics-lab.com/downloads/schematic/006/



More comprehensive list of software options to browse

www.epanorama.net/links/software.html#schemaedit

[David E. Clark]

The link to the website containing the Bentley Manual (#1 in the list at the top) has been removed to comply with board policies.

This is still a great resource. I've been adding to this list a couple of times a day. Check back often!

If you want to PM me with any links or resources you have, I'll make sure they get added to the listing at the top.

[David E. Clark]

Because of space limitations, and to give them a more prominent position, MFI Technical Message Board Postings are listed and described in this thread: MFI Message Board Index.