F I N K B U I L T

Scale model cockpit FPV

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

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

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

The Nothing Box

nothing box

Thunderbirds

Thunderbirds are go
Are Go!

Command Center

command center
Sweet assemblage spaceship’s bridge.

Four Drano’s

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

Toothpaste Aerosol

toothpaste aerosol
Aerosol toothpaste




DIY Fuel Injection Conversion

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megasquirt

Advanced car hacking

What’s a Megasquirt?

Megasquirt is an affordable, open-source, DIY engine management computer that you assemble yourself. A large community of developer/users provides for constant development, and great free support.

Me and cars

My car ownership history to date looks like this:

  • 67 Karmann Ghia
  • 74 VW Bus
  • 69 Saab 96
  • 76 BMW 2002
  • 67 Saab 95
  • 73 BMW 2002

One common thread that runs through this list is that these cars all have simple, old, carbureted engines. They have only fundamental automotive electrical systems, with the only real electronics being the instruments and radios, if they even had that. No Check Engine lights here.

I am attracted to these vehicles not only because they are stylish old Euro-cars (capable of surviving a neutron weapon attack), but also because they are cheap and easy to maintain by the self-taught home mechanic. Although I do admire the performance, and “driveability” of a modern, computer-controlled fuel injected car, I have never really wanted to own one.

Not User Servicable

Modern, EFI engines have always intimidated me. I had no idea what all those black plastic boxes, or that tangle of hoses, valves, and wiring was for, or where I would start when it came time to troubleshoot a performance problem. How do you talk to you car’s brain to find out what is really bothering it? You don’t. Automotive ECUs are closed, black boxes of mystery, certainly not user-servicable, not flexible or configurable.

No interest.

After the Engine Rebuild

When I recently rebuilt the engine in my 1973 BMW 2002, I included some performance upgrades, such as higher compression pistons, a longer duration camshaft, and a bigger-bore carb. I was astounded at the increase in throttle response and torque with the new setup, but I just couldn’t get the carb tuned the way I wanted it. There was a bad “stumble” at low speed, and horrible fuel consumption. After a string of jetting experiments, I went back to a smaller, smoother carb (Weber 32/36), but of course, there were some performance trade-offs to live with as a result.

I have been driving in this smooth but de-tuned state for a while now, but knowing that there is a better engine under that hood, just waiting to be let loose, was driving me nuts. So, I started collecting parts to convert my engine to Electronic Fuel Injection using Megasquirt. From what I gather, EFI will deliver both performance and economy. Sign me up.

megasquirt

If you are not intimate with the workings of EFI systems (as I wasn’t), take a look at this Megasquirt wiring diagram.

Pretty much the only things in this diagram that my car has now are the battery, ignition coil, and switch. The rest has to be cobbled together and adapted to my motor. There is also some stuff that isn’t in that picture, such as an air intake manifold, throttle body, and cold air intake, and idle control components. This is by far the most ambitious automotive tinkering that I have taken on to date.

Wideband Oxygen Sensor

Before I had actually commited to going EFI, I decided to install a wide-band oxygen sensor to help me get the carbs dialed in. This was extra satisfying for me because an o2 sensor is a vital part of a fuel injection system, something that I aspired to add some day (and that day has come), and therefore this was a dual-use item for me.

A wideband o2 system consists of an exhaust gas oxygen sensor, and a seperate controller. The controller interprets the voltage from the sensor and displays it to you (or to another controller) as an Air/Fuel ratio.

I chose to install the Innovate LC-1 Wideband controller, as well as a little numeric LED display that shows me current AFR.

megasquirt

The LC-1 also does some datalogging, and comes with software that lets you save the logs as well as read them as graphs and tables.

Since my car did not previously have an oxygen sensor, I brought my exhaust header downpipe to a muffler shop and had them weld in the threaded sensor bung that came with the LC-1 kit.

megasquirt

The wideband o2 was indeed a huge help in figuring out the ideal carb jetting. Without the AFR data, jetting a carb required alot of chicken bone necklaces and voodo peace offerings to the jet gods, to get it right.

megasquirt

Parts buying spree

A recent infusion of cash from the sale of my motorcycle sent me on a massive EFI parts buying spree, and propelled me into full and immediate comittment to the megasquirt project.

I pretty much have everything I need for the converion either on the way, or in the works. The sexiest part so far is the medusa-like air intake manifold that came from an 84 318i. this will bolt right up to the 2002 head, and has the injector ports cast right into the manifold.

Some people go with individual throttle bodies, which gives a more period correct and racey look, but presents a bit of a problem, since Megasquirt relies heavily on Manifold Absolute Pressure for mixture control.

megasquirt

megasquirt

I am using a throttle body from an E30 325is, which has a 2.5 litre engine. This should flow plenty of air for my warmed-over 2 litre. TB shown here next to the smaller 318i throttle body that came with the manifold.

megasquirt

Assembled “stimulator”

I ordered all of my controller related kits and components from DIY Autotune, who supplied me with a kit for the main controller board, a relay board, and a Megasquirt “stimulator” kit, which is a little potentiometer board that emulates inputs from the engines’ sensors. You use the stimulator to test and troubleshoot the main controller board while you assemble it.

megasquirt

Unasembled Megasquirt controller board

Next up: Assembling and testing the controller.

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31 Responses to “DIY Fuel Injection Conversion”


  1. jovial_cynic Says:

    ah – awesome! I plan on running Megasquirt on a 1971 Datsun 510 I own. Keep up the good work and great documentation!

  2. der5er Says:

    I’m watching with baited breath!!! That is going to be awesome! I’m betting you’ll learn (and end up teaching) quite a bit. I’ve posted this to the mye28 community, there’s a few 2002′s on the board, so I’m sure you’ll have others watching as well. Good luck!

  3. E.K.W. Says:

    You’ve already got me looking hard at every used 2002 I see, and now this.

    My wife wants to have a word with you, I suggest feigning ignorance.

  4. dr. calamari Says:

    You’re a braver man than I, to attempt this conversion (although it seems like the results will be well worth the effort) to EFI. Do you have a backup car to use while all this conversionating is taking place…just wondering!

  5. Scot Says:

    I am just now ordering the Pertronics electronic ignition module for mine so I can start driving it again. Can’t wait to see how your EFI experience goes though. That will be too freaking cool. I have an oversized carb on mine too, that some previous owner thought was a good idea, and the too-rich exaust smell is pretty obvious along with less than spectacular throttle performance. Upper end of the band is fun though. ;^)

  6. jacob Says:

    This is so awesome, can’t wait to see the project continue.

  7. Stuart Says:

    Great post, just wondered whether you’d seen the VEMS group system http://www.vems-group.org/

  8. diten Says:

    I get to the Megasquirt site, researching for info on building (my own, complete) EFI, I like microcontrollers and electronics, but being a hobbist in that field, design the complete setup was a big proyect for my little free time. I never started this proyect, but i think that Megasquirt is a very intresting option, i think that i will buy a kit in the future. I hope you get so good result on you BMW (and blog about it) that you want to do this conversion to your VW Bus, cause, I have a 69 VW Bug (my main question once the conversion is done, is the parameters table)

    Steve says:

    Check out the Megasquirt forum, you will find lots of people willing to share their configuration files.

    Your blog is inspiring (and very nice looking too), and make me want take back the idea of the conversion. thanks.

  9. bob Says:

    Just a tip, since I don’t see it mentioned in your diagram. For the fuel supply, you’ll either need to add a baffle to your fuel tank, or build an under-hood in-line tank that is fed by a low pressure pump to it. The high pressure fuelie pump then pulls out of that tank and returns to that tank. The low pressure pump feeds the tank from the bottom, and once it is full a return at the top of the tank is plumbed back to the fuel tank. The high pressure side draws from the bottom of this tank and returns to the top of it. If you don’t do this (or baffle your tank or put a baffled tank from an EFI vehicle that fits your 2002) your high pressure EFI pump will suck air from the unbaffled stock tank as the fuel sloshes around, which is a much bigger deal for an EFI vehicle than a carb’d one. The system I’ve described is used by off-roaders who run EFI engines and encounter extreme angles … they run tanks like these in addition to baffles in the fuel tank. The aux. tanks need not be too big, I think a quart or 40oz would be plenty for you. I’ve seen pictures of this on the web, but I can’t seem to find a link for you right now. The guys over on the megasquirt forum should know about this and be able to help you, though.

    Good luck!
    Bob.

  10. bob Says:

    It’s a surge tank …. don’t know why I couldn’t remember that!

    You can build one pretty easily, or there are some commercially available options.

  11. Jeff Says:

    Great write-up! I have already Megasquirted my ’95 Probe GT (and turbocharged it to over 300whp reliably).

    I have a 1980 MGB and have been thinking about Megasquirting it to get rid of the very problematic (primarily due to the “automatic” choke) single Zenith carb.

    Since my 1.8L was not put into cars (to my knowledge) past 1980, I am planning on making a custom intake manifold and use some sort of TBI from a similar sized motor to avoid fabricating fuel rails.

    I found your site because of Bob’s mentioning of the surge tank and that’s what I was searching for to avoid having to put baffles in my 26 year old gas tank.

    Thanks for the write-up. And yes, DIYAutoTune.com is a great site with great customer service!

  12. Azz Says:

    hey sounds like a good project but was wondering is well, i have a 94 lancer carb and we are about to strip my mates nissan pinty is there any am i able to jus take all of his efi part and put them in my lancer or am i gonna have to get more components

  13. Jim Fedor Says:

    I started building a Megasquirt last year. I am putting it on a 37 ford flat head engine that I am putting in a motorcycle. I am trying to hook up the sensors and I wish I had a really good schematic for it. Any help? Jim

  14. Steve Says:

    Jim,

    There are lots of diagrams on the megasquirt site.

    AND, please let me know when you get your project done, it sounds great!

    steve

  15. David Ellis Says:

    I Megasquirted my ’73 MGB earlier this year after about 18 months of R & D. My system has an MSX cross flow head (1 intake port per cylinder please-no siamese problem here), a Pierce dual DCOE intake manifold, 2-TWM throttle bodies (designed as direct replacements for Weber carburetors). Since all the throttle bodies and manifold equipment are now located over the distributor, I opted to convert to a EDIS ignition system from an early 90′s Ford Escort, thus enabling me to tune and time the engine with the Megatune software on my laptop computer.

    So much for background. To Bob’s point regarding the fuel system. Sloshing fuel and sucking air is never good for any EFI system. the surge tank and Bosch high pressure fuel pump from a fuel injected mid to late 80′s VW Jetta or Golf is a geat add-on system. It fits in the right side battery box perfectly. It’s designed as an external surge tank so it has all the supply and return fuel line attach points to and from the fuel tank and to and from the fuel rail. I consider adapting the surge tank to fit in my ‘B’ was one of several good solutions to potential unreliability problems down the road. Upgrading the 30 amp rebuilt Lucas alternator to a Saturn 110 amp model is another one.

    Happy squirting,
    David

  16. vic myers Says:

    David- Tell us more more more. How is that frankenBee running. MayGawd, a EFI Cross-flow….must be heaven on earth. Can you share some detail on engine specs before and after MegaSquirt? Thanx, Vic BBS MGB Technical Threads has lots in archive on swirl pots.

  17. David Ellis Says:

    Vic – I’m still working out some small bugs, but the initial software set-up, configuration, and mapping went better than I had ever imagined. I haven’t had it on a dyno yet but by the way it pulls off the line and accelerates at highway speeds my gut feeling is that it has well over 100 HP now. Most of that power is attributed to the engine build-out, not EFI. The engine starts immediatly no matter what temperature it is and stops as soon as I turn the key off. No dieseling or run-on at all. And I’m amazed at how smooth the engine runs too. On the original restoration back in 1999, I had the engine bored out to .40 over, everything was balances, and the flywheel was lightened. When I put on the X-flow head I had it polished and ported to the DCOE manifold so it flows as well as it can. I’ve not seen a huge jump in fuel economy yet but I expect that will show up after dyno testing. The bug I’m working on now is in the tachometer. Seems the tach is showing only about half the engine rpm. I think it needs more electronic stuff.

    Thanks for asking,

    David

  18. Tom Says:

    Did you ever resolve your tach issue?

    I’ve tried bridge D1 and D2 with 100K resistor. My TACH works up to about 2500 and then drops.

  19. Steve Says:

    Tom -

    Yeah, my tach worked great once I put a resistor in the circuit, but I think that mine was a lower ohm value. I just used what I had on hand out of desperation and it worked. I think that it was 15K.

    steve

  20. vic Says:

    David- I’ve started my DIYEFI on the cross flowed MGB. Any chance I could get your proto-map soas to get up and running? I’m instally the EDIS first, then the EFI. Has your tach issue been resolved?

  21. Danny Says:

    would a 320i intake manifold bolt right up to the 2002 head? or will only the 318i?

  22. Steve Says:

    Danny,

    Yeah, the 320i intake will bolt on, but you run into some issues fitting the fuel rail and injectors. See this link for details:

    http://www.hbci.com/~tskwiot/2002.html

  23. DIY Fuel Injection Conversion | PyroElectro - News, Projects & Tutorials Says:

    [...] There are lots of pictures & stats to help you through the installation process. PyroFactor: Read Permalink  |   Email This [...]

  24. efi conversion... please help - Benzworld.org - Mercedes Benz Discussion Forum Says:

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  25. vic Says:

    David- Any chance the medusa manifold off the 1984 318i BMW will port match to the MGB X-flow???
    Has anybody found a match to fit the x-flow, since I do not want to go TMW, and rather prefer ITB’s (using the 650GRX motorcycle EFI setup featuring 38 mm TB).? Vic

  26. steve mccormick Says:

    i am looking for a way to make-get a control module to add-replace the ecm for my motorcycle. It is a fuel injected (factory) 2003 honda VTX 1800 2 cylinder v twin. I would like to be able to adjust the ignition timing, and mixture, and possibly the rev limiter. thx

  27. steve mccormick Says:

    i am looking for a way to make-get a control module to add-replace the ecm for my motorcycle. It is a fuel injected (factory) 2003 honda VTX 1800 2 cylinder v twin. I would like to be able to adjust the ignition timing, and mixture, and possibly the rev limiter. thx

  28. steve mccormick Says:

    i am looking for a way to make-get a control module to add-replace the ecm for my motorcycle. It is a fuel injected (factory) 2003 honda VTX 1800 2 cylinder v twin. I would like to be able to adjust the ignition timing, and mixture, and possibly the rev limiter. thx

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  30. Find drycell batteries Says:

    It’s a surge tank …. don’t know why I couldn’t remember that!

    You can build one pretty easily, or there are some commercially available options.

  31. radio watch Says:

    Great write-up! I have already Megasquirted my ’95 Probe GT (and turbocharged it to over 300whp reliably).

    I have a 1980 MGB and have been thinking about Megasquirting it to get rid of the very problematic (primarily due to the “automatic” choke) single Zenith carb.

    Since my 1.8L was not put into cars (to my knowledge) past 1980, I am planning on making a custom intake manifold and use some sort of TBI from a similar sized motor to avoid fabricating fuel rails.

    I found your site because of Bob’s mentioning of the surge tank and that’s what I was searching for to avoid having to put baffles in my 26 year old gas tank.

    Thanks for the write-up. And yes, DIYAutoTune.com is a great site with great customer service!