Scale model cockpit FPV

cool scale cockpit video

Funny Zoo Snap

man enjoys elephant My wife noticed this in the family archives.

RC Nitro motorcycle racing

rc motorcycle Motorcycle racing in Lilliput.

Manned RC Multicopter

manned multicopter
Here’s an RC multicopter big enough to ride on!

Make: Talk 004

make: Talk 004
I had a fun time talking to Mark Frauenfelder in episode 4 of his new podcast, Make: Talk!

One Man Basement Band

one man band
I feel like I could be getting more mileage out of my right foot.


liberty vintage motorcycles An Etsy portrait. Thanks, Danny.

Tequila Sleeve

tequila the champs
Champs sleeve

Wolf-Stelzer Book Lamp

Book Lamp
My friend Tess just made the cover of ReadyMade with her cool lamp design.

Tree Stump Bug

Can this be for real? The design is so awesomely Thunderbirds. Via

The Nothing Box

nothing box


Thunderbirds are go
Are Go!

Command Center

command center
Sweet assemblage spaceship’s bridge.

Four Drano’s

Watch the sink slowly, all but disappear from the design .

Toothpaste Aerosol

toothpaste aerosol
Aerosol toothpaste

Fuel Injection Conversion Complete

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electronic fuel injection

Project Megasquirt finally comes to a successful close. Last time, I got the computer installed, and interfaced it with a Ford Electronic Distributorless Ignintion Sytem. The final step in doing a complete programmable electronic engine management retrofit to my 1973 BMW 2002 was to install the fuel injection system.

Intake preparation

I used the intake manifold from a 1984 E30 318i, which ran a late derivative of the same M10 motor that is found in my ’73. I chucked the puny throttle body from the 1.8 litre engine, and bolted up a 58mm TB from a 325is using an adapter plate jointly developed by myself and Tom rafalski at 02 Again.

electronic fuel injection

I bent up a couple of throttle cable brackets from some 1/8th ” steel and bolted those to the bottom of the manifold, and hooked the cable to the throttle body. The throttle body also recieved a throttle position sensor, Intake Air Temp sensor, and an air intake boot from a 325is.

Idle control

For idle control, I plumbed in a VDO Idle control valve. Megasquirt sends a Pulse Width Modulated variable current to the valve to open and close it as needed during engine warmup (based on coolant temperature).

Update: The E30 type VDO idle valve does not really work very well with the PWM circuit modification as outlined in the MSIII manual. The circuit was designed to drive a Bosch or Ford type idle valve. I will be switching to a Bosch valve soon.

electronic fuel injection

Fuel supply

In its carburetted state, the 2002 uses a plastic (low pressure rated) fuel feed line. The fuel return line runs beneath the car, and for durability, is made of steel, so I did what others before me have done, and reversed the feed and supply lines using the steel as a high pressure feed, and the plastic line as a return to the tank. All flexible lines were replaced with proper high-pressure rated fuel injection hose.

electronic fuel injection

I removed the cylender head mounted mechanical fuel pump and blocked it off with another nice Tom Rafalski piece.

A Bosch high pressure elctric pump was mounted to the subframe near the tank, using some split rubber hose, conduit clamps, and a couple of 1 penny washers.

I went with Bosch #24/hr high impedence injectors, which are driven straight from the Megasquirt relay board without the use of resistors.

electronic fuel injection

When you are at the yard getting your intake manifold, also grab the water distribution neck, fuel rail, pressure regulator, and the coolant bypass pipe.

Romove the old

Your stock intake manifold is water cooled (or is it water warmed, I’m not sure) so when you yank the carb and intake, you will need to route the coolant straight back to the heater. The 318i water pipe works great for this, so grab it. I had previously installed the smaller M3 starter motor, but if you have a stock starter, you will have to trim down the bracket to make room for the new intake manifold. You might as well take the opportunity to upgrade to the more powerful and smaller M3 starter now.

electronic fuel injection

Throttle Linkage

To transfer the up-and-down motion of my old throttle linkage rod, to the pull-a-cable action of my new setup, I made a simple bellcrank linkage out of aluminum ( inspired by the engineering work fellow bmw experimenter Mike Koch). The bellcrank mounts to the brake booster bracket. I cut about 3 inches as required off the end of the linkage rod and threaded it to accept a rod-end bearing, which bolts to one end of the bellcrank. The throttle cable hooks to the other end.

electronic fuel injection

electronic fuel injection

So, there it is, done. Of course, it is never really done, as there is an endless amount of tweaking to do. There are Volumetric Efficiency tables to tweak, Air fuel ratio maps to optimize, and accelleration enrichment settings to fine-tune. You never feel that it is quite perfect. But one thing’s for sure, it’s a huge improvement in performance and tuneability over the old weber downdraft.

electronic fuel injection

Finally, my once high-tech sports sedan can keep up with today’s econo-box hybrids.

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34 Responses to “Fuel Injection Conversion Complete”

  1. WooHoo Says:

    Woot! I get to be the first to congradulate you!!!

    I converted an ’84 Vette from TBI to Multiport. Though I use the edelbrokk pro-flo 3500 kit. It was still alot of work with gratifying results! It seems to that the tuning is the hardest part. For the fisr couple months my car would have good and bad days as I searched for just the right mappings.

  2. Peter Says:

    I’m impressed. It looks pretty as well.

  3. Jonathan Says:

    Absolutely outstanding and clean! Excellent job! Any plans on going into more detail and posting your config file?

  4. Johnsim Says:

    Nice install, very clean. Will you post more pics of the whole car. You should contact Bimmer mag about your project.

  5. Steve Says:

    Hey Jonathan,

    I used tims config file ( here ) as a baseline for AFR, VE and spark advance, because he has the same cam and CR as me (292 deg, 9.5:1).

    pretty much everything else will be car-specific, based on your parts etc…

    Johnsim, here is an interior and an exterior shot of my Rivierra 73.



  6. Johnsim Says:

    Nice, well done ’02. Wish my 90 325ic looked that good.

  7. Clay Says:

    Great job. The car looks great. I’m planning on doing exactly this over the next 4-6 months.

    Would you mind emailing me so that I might throw the occasional tech question your way?


  8. bob Says:

    No surge tank? :)

    Not that it’s _required_, but I thought I had you convinced! Nice job, looks great.

  9. Steve Says:

    Bob –

    You caught me!

    I will put in a surge tank if I ever have problems. I kind of ran into a time crunch.

    Clay – email sent.


  10. Dave Says:


    Awesome ’02 job – should be in a mag. Have you toyed around with the idea of throwing in a turbo system?

    I’m following in your footsteps but am only at the point of getting a weber 32/36 in place of my single barrel solex… any tips on jetting sizes for headers(02again) w/ ansa sport exhaust ?

    Any chance on shooting me an email so I could send a quick tech question here and there?

  11. Steve Says:

    Dave, Turbo is tempting, but I am running a 292 cam, and Mahle 9.5:1 piano top pistons, so forced induction may not be the best way for me to go.

    I will dig up my old webber jetting for you.


  12. Jonathan Says:

    What pins on the MS box did you connect the idle control valve to? I’ll pretty much have the exact same setup once I get to the engine rebuild.

  13. Steve Says:


    I think its pin 30 out of the MS. I used the relay board, which has a terminal marked “fidle”.

    But, dont use the E30 VDO Fidle valve like I did, it doesnt work very well. The PWM modifications that are outlined in the MSIII manual are designed to drive a Bosch or Ford valve.


  14. Hugh Says:

    Killer Steve… You really should submit this to a magazine and get the rig in print.

  15. Roy Says:

    My 02 is currently running 85 318i L-jet injection, 318i cam and ignition system, and bored out throttle body which is still only about 48 mm. Driveability and bottom end power is great but lacks power at the top, say above 5000 rpm. At this point, I’m tempted to try the 325i throttle body and adapt a larger air flow meter but if that proves impractical I may go your route with the mega squirt. A couple of related tips for you: the in tank fuel pump and sending unit from a 89-90 BMW 325i fits the pre 74 02 fuel tank perfectly so no need to hang a pump anywhere. Bosch AL42x alternator that fits 77 630csi fits the 02 bracket perfectly and gives you a 65A charging system, eliminates the trouble prone rubber bushings and external regulator. The only mod necessary, is once your pulley is installed the shaft will stick out too far and needs to be cut off using a “cut off wheel”.

  16. Dane Says:

    Man, this writeup is beautiful as is your car!! I cant believe I found this (just in time for my conversion to EFI) writeup! Is there a way that you can email me as you did the other posters so I can ask technical questions? It would be greatly appreciated.

  17. carlos ortega Says:

    hola! soy distribuidor de sensores de full injection y me gustaria saber si tienen sensores en oferta. gracias

  18. John Says:


    I finally got my EFI conversion complete, from fuel to spark. Unfortunately my engine bay isnt as clean as it used to be but oh well. Here’s a link: http://www.designmills.com/category/cars/

  19. Paul Says:


    Very nice job! Very clean work! Just the kind I like to do myself. If you wouldn’t mind, what was the approximate cost of the ignition setup? I have always wanted a crank fired ignition for my 2002. I have always had trouble with setting up the carbs along with the timing.



  20. Marc Severin Says:


    Very nice! And thanks for posting on the FAQ. I have decided to convert my car to the following: Schrick 292, 9.5:1 comp., S-14 crank, essentially a 2.3 Stroker. I am going the same route as you. ’91 Ford 1.9 EDIS system and Megasquirt using the 318i manifold and 325 throttle body. I am also going to contact 02 again for his exhaust header and new downpipe with sensor.

    So are there any changes you would make if you were starting again? From the looks of things I think not. I’m hoping to contact you if I have any trouble. I’m even going to use a similar throttle linkage. I can’t wait to come into the new medium. It is simple, 10 years from now I want to jump in my car, start it, have it idle smooth and run forever. Thanks!

    Email me back, that would be great!

  21. Burt Aderholdt Says:


    Wow very impressive job. I love your attention to detail and tidiness. I’d like to ask you a question if you don’t mind. I’m about half way finished with my Megasquirt EFI conversion on my 77′ 320i and I’m using for the most part the same basic kit as you… 318i manifold etc.c except I already had crank fire with an HPX unit and I went with a Ford Mustang TB. My question is this, what is the round filter looking object that you have mounted in line on the downstream side of your fuel pressure regulator? I keep seeing them in photos of EFI conversions using the 318i manifold and fuel rail. RealOEM shows them in the exploded diagram on early e30 318i’s but lis tthem only as “connector”. Is it some sort of check valve or something. Does the regulator need this part to function properly? Thanks for your time. And once again, beautiful job.


  22. Steve Says:

    Hey Burt,

    Well, if I remember correctly, that little thing is for dampening the pulses from the fuel pump, but I dont really see how it could do any good on the return side, but then agian, I am no expert on fluid dynamics.



  23. David Sword Says:

    I am considering this system for my 2165cc VW. Am I right in thinking I can pretty much copy your system? I know the intake will have to be built different. Can you tell me if the Ford ignition will work?

  24. Steve Says:

    David –

    Yeah, the EDIS should work great on your motor. I’m sure that a google search would reveal some Megasquirted VW’s



  25. Mark Stumm Says:

    I am working on a Megasquirt project for an S14 E30 M3 motor in my 75 2002. How did you wire your injectors for the relay? Bank 1 (1 & 4) and Bank 2 (2 & 3), or Bank 1 (1 & 2) and Bank 2 (3 & 4)?

    I also plan to use the fiddle circuit to drive a Bosch IAC instead of the stock E30 Valve. I hope you write-up your experience so I can learn from your experience.

    Great work, very inspiring.

    Steve Says:

    “Hey Mark,

    Honestly, I don’t recall having to make any decisions at the wiring stage. I used the Megasquirt relay board kit . I think that the instructions told me how to wire the controller to the board.

    Once you are up and running, you set up the firing order and injector control scheme that you want to use in Megatune.

    I hope that this helps.”

  26. stu mitchell Says:

    hey this is a great write-up! i’m finishing a similar project built by my high school kids…although we’ve built it with the older 68hc based megasquirt…ms1 with megasquirtnspark. any suggestions on tuning? is it possible to adapt tims file to work with the older ms1? and your engine bay…WOW. tidy i’ll tell ya.

  27. Gary edwards Says:

    i want to know if anyone converted their car to run on water and fuel

  28. Bozo Says:

    I’m too thinking about converting my carb fuel system to injection and i’ve been doing some researches.
    I looked at the fuel system diagram in the first page of this article and i’m surpirsed that it doesn’t have a crankshaft potition sensor in it, which tells your ECU what and when to open each injector.

    Bozo, see page 4 of the article.

  29. cesar Says:

    ohhhh!!! congratulations for you!

  30. paul Says:

    Did you have the trigger wheel made?

  31. Jonathan pH Says:


    Your blog has been invaluable in planning my megasquirted 02 project but I’ve got a few questions. I know this post is pretty old but I’d really appreciate the help. Maybe you could email me?

    What cold air intake tube and filter did you use? Those things are damn expensive and I want to make sure I get one that fits the rubber elbow on the 325i TB. I don’t want one that expects me to have a MAF sensor in line with it.

    What did you do with the crank case vent? did you put a PCV valve on it and hook it up to the throttle body or just let that tube hang or something?


  32. Simon Says:

    Hi Steve,
    Thanks for your story. Your 2002 was the inspiration to megasquirt my M10 powered BMW. It took a lot longer (and cost more!) than planned, but today I got it running at last. The practical help out of this story was the directions to Tom Rafalski, and the config file above.
    Thanks again!

  33. Wayne Says:

    Hi Steve!

    What a fantastic build! Congrats!

    I have a E12 518i and the K-Jetronic system is acting up. The K-Jetronic is almost all-mechanical, but the tolerances are very fine, so it makes it impossible for the “user” to fiddle.

    This is just what I need. If I may ask, what was your total spend?

    Again, congrats on a job well done!

    Wayne (South Africa)

  34. 3world_boy Says:

    I am chaniging my M10 engine from carborator to ingectionm, you mentiond that you changed the fuel pomp ( beacause it was machanical) with an electrical one, so my question is ….
    How did you wired the pomp ??? directly to the battery, ore did you fited a FUSE and a RELAY … and of corese a switch