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

ECU and Distributorless Ignition

« [1] [2] [3] [4] [5] »

BMW 2002 crank pulley

After months on the bench, the Megasquirt ECU is now officially in use in the car. For ease of access and simplicity, I decided to mount both the computer and the relay board inside the glove compartment. I almost never wear gloves in my car anyway.


The Megasquirt II is capable of handling both fuel and spark. After reading about the Ford EDIS (Electronic Distributorless Ignition System) on the web sites of some BMW 2002 EFI pioneers like Tim Skwiot and on the Megasquirt site, I decided to go for it and ditch the distributor.

Most people seem to do the fuel injection first, then upgrade later to computerized ignition. I decided to do it the other way around, since I wanted to trigger the Megasquirt from a VR or Hall-effect sensor rather than a coil signal, and once I had the trigger wheel installed, it was a simple matter to install the rest of the EDIS. Once I have the EDIS/Megasquirt dialed in, I will move on to the fuel.

EDIS uses a toothed crank pulley trigger wheel and variable reluctor sensor to read engine position, which it passes on to the Megasquirt, where the ignition advance table is stored. The megasquirt then shouts back to the EDIS module how much to advance the spark for a given RPM/load/temperature, and the module fires off the coils accordingly.

BMW 2002 crank pulley

I ditched my heavy, cast-iron smog pump crank pulley in favor of the Euro-spec stamped steel, single groove pulley, which I sent off to my old standby 2oo2 machinist Tom Rafalski over at 02Again. Tom machined up a steel shim to adapt the trigger wheel to my pulley. All I had to do was bake the trigger wheel in the oven and slip it onto the pulley. Shrink-to-fit!

EDIS trigger wheel

I mounted the VR sensor to the motor with a simple aluminum bracket which was attached by 2 of the water pump bolts.

BMW 2002 crank pulley

Once I had the trigger-equipped crank pulley installed, I set the sensor gap to about .5 mm.

EDIS trigger wheel

I slapped in the rest of the ignition components (module, coil, and wiring) and gave the old key a turn.

Much to my amazement, the car started right up on the first crank. Look Ma! No distributor! Even without a signal connection to the megasquirt, the EDIS will function in “Limp Home Mode” at a fixed advance of 10 deg. BTDC.

I installed Tim’s configuration file to get me started (my car reads XML, how cool is that?). Now the tweaking can begin.

Update: No ignition table tweaking needed. Tim’s advance map is fantastic. I had a slight mis-understanding about where to set the baseline timing for “limp home mode”. I essentially had the VR sensor 1 tooth off. To correct this in software, I set the “Trigger Offset” parameter in MegaTune to -10. At some point, I need to physically reposition the VR sensor so that “limp home” will be optimal. Once that confusion was cleared up, I was off to the races.

BMW 2002


So how do I like it?

It’s amazing .

I knew that ignition timing was an important variable in engine performance, but I honestly didn’t expect this much improvement. The motor runs so smoothly throughout the RPM range, it just climbs and climbs. I can’t keep my foot out of it. Totally programmable, solid-state ignition with vacuum (MAP sensor) advance works really well.

Distributors are kind of garbage.

I can’t wait to install the fuel injection.

« [1] [2] [3] [4] [5] »

17 Responses to “ECU and Distributorless Ignition”

  1. bre Says:

    Just a note to let you know I am living vicariously through you and your car. I sold my 544 and don’t have a project car right now. That is one clean engine compartment you’ve got there… drool.

  2. Mcewan Says:

    This is amazing! The glovebox remake is elegant and inspiring. I know this is a stupid question, but tell me anyway. You have replaced hardware such as the distributor, with software. What happens if one of the computer-controlled systems fail? Will the car continue to run?

    Janie Mac

  3. Steve Says:

    Well, if the Megasquirt computer were to fail to send a spark advance value to the Ford ignition module, the module will default to running at a fixed 10 deg. advance. This is the ignition’s “Limp Home” mode.


  4. John Says:

    Wow nice install, more pictures of the rest of the car, please. Wonder if it work on 90 325i.

  5. Clay Says:

    Regarding the trigger wheel install…….how do you line it up? Does the missing tooth line up with the notch in the pulley? Also, how do you know where to mount the VR sensor?

  6. Steve Says:

    Clay, read this:

    EDIS Info

    Mount the VR sensor first, where it is convenient. Then mount the trigger wheel so that the missing tooth is is in the correct position, which depends on your engine’s number of cylinders.

    For a 4 cyl. engine, the missing tooth should be exactly nine teeth (90°) ahead of the VR sensor with the motor sitting at TDC on piston 1.

  7. Clay Says:

    What kind of gas mileage are you getting with the EDIS? I’m curious what you’ll see with EFI, also.

    Oh, are you running a 5 spd.? What’s your diff ratio?

  8. Steve Says:


    I am running a 5 speed and a 3:91 rear-end. I am getting about 30mpg on the highway, and 20mpg around town. Very carelessly calculated, but there is a BIG difference.

    I do expect to get better mileage around town with the Injection, but more importatly, better Throttle-response and overall performance. I also have a lightened flywheel, and I am in bad need of a limited-slip!

  9. Clay Says:

    Hmmm…..WHat year is your car? You don’t happened to have a longneck diff, do you?

  10. Clay Says:

    Oh, and have you had any problems running the Megasquirt without the EFI stuff attached? I’m looking to follow the same path as you in running the EDIS stuff first, then getting the EFI stuff later, when the budget allows. I just wonder if the unused signals and power (as to the fuel pump and such) will harm the ECU. Any thoughts?

  11. Robert Says:

    This is awesome and exactly what I want to do with my ’75 2002! I don’t think I’ll go with the EFI conversion ’cause I have a couple of 40 PHH’s that I want to keep but the distributor is a nightmare. Now to figure out what’s needed for just the EDIS conversion.

    Thanks for the blog!

    ps. cool stop motion video from Tacoma to Seattle! I like the accompanying track. Well done.

  12. robert verhey Says:

    I’am busy with building a EDIS system in a Willys Jeep 1955. The distributor was very worn out. Where did you buy the 32-1 tooth trigger wheel?


  13. Joe Torres Says:

    Looking for information on where to purchase a trigger wheel for a Valkarie. Any information will be greatly apprectiated.

    Thank you.

  14. Matt Says:


    Can you preset the position of the wheel so that “limp home” woudl effectivly be 20 BTDC?


  15. Steve Says:

    Matt, Yes you could.

  16. wildman Says:

    dude ms has a setting called offset.. this will put the 10% anywhere ypu want. zero is best then your map is actual advance.

  17. Steve Says:

    Wildman –

    Very true, but if you lose the MS computer for some reason, you can still drive home in “limp home” mode. In that case, the actual physical position of the sensor is important.