Designed these for my 914 and bus megasquirt projects but built a batch of 10 while I was at it in case anyone else found them useful. Specifics...

This is a 24-2 trigger wheel and sensor that mounts inside a Bosch distributor (009, 035, 050, etc) and uses a Hall effect pickup to generate a trigger signal for coil on plug or wasted spark ignition systems. Installs in 5 minutes and is much more discrete than all of those on crank 36-1 VR based systems with the brackets, etc. Tested on VW/Porsche type 4, VW type 1, and Porsche 356 and 912 engines, but will fit a broad range of Bosch 4 cylinder distributors. Can parallel two wasted spark coil packs for twin plug applications. I recommend the VW 2.0 coil pack VAG part 032905106B/032905106E which fires with logic level signals rather than requiring ignitors.

Uses the Allegro 617 hall effect sensor. This sensor is internally pulled up to the power supply with a 10k resistor, so if you need a 5 volt square wave output (logic level) then power it with five volts. Need 12V? Power it with 12 Volts.

3 wires, power ground and signal all in a shielded cable ~5 feet in length.

Wheel is a 24-2 which looks like a 12-1 on the crank. Will work with most Megasquirts but please do your research.

I currently have 10 in stock and ready to ship.
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You can verify this, but, if it fits the 914 disty, it should also fit the Mercedes 4 cylinders of that era. (I am pretty sure it will fit my 1966 MB 200.)

In other words, you can expand your potential marketplace.

-- brett

Could this setup also be used to trigger the injectors on a stock D-Jet ? Thereby eliminating the trigger points. if so, I want one or more.

Bfrymire: Yes, I suspect it'll fit a lot of Bosch 4 cylinder applications. Bosch was remarkably consistent in the geometry of their distributors. So likely add to that list Saab, Volvo, Alfa, VW etc. A lot of L-jet and CIS cars used an ignitor in place of the points with spark still running through a cap, so they're kinda halfway systems that many don't bother to upgrade to full distributorless ignition.

Pilothyer: If you only want to eliminate points, you can use the Pertronix system which replaces points with a hall effect sensor and ignitor, advance is then still handled by the distributor. I recommend getting the 2nd generation that doesn't burn out if you leave the ignition on while the motor is not running (like listening to the radio with motor off).

My system provides the reference trigger signal to a fuel injection and ignition controller. The stock 914 fuel injection does not control ignition, it uses the firing signal on every cylinder to batch fire the injectors, the rest is handled by a classic points/cap/rotor system with advance dictated by springs, weights and the vacuum pot. The megasquirt (as an example of an aftermarket ECU) can control various types of ignition systems and fuel injection (batch or sequential). For injection the aftermarket ECU just needs a firing signal like the stock would, but for ignition it needs to know the position of the crank (for wasted spark) and/or the position of the cam (for coil on plug). Wasted spark is the easiest way to go. Just to do ignition you could use a Megajolt controller, but for the price and effort you might as well get a megasquirt and give yourself the possibility to upgrade to injection control later. I normally recommend doing one or the other first, get it running, then move to full FI + ignition control. A megasquirt 1 running MSexrtra code ECU is around $200 from DIY Autotune and works perfect in our machines. The fancier versions add control for modern thing like drive by wire, sequential injection (primarily used for fuel economy), various sensors and controls our cars do not have (stepper air idle control for example). Anyone interested in more info please feel free to ask.

Jarred

Pilothyer: If you only want to eliminate points, you can use the Pertronix system which replaces points with a hall effect sensor and ignitor, advance is then still handled by the distributor. I recommend getting the 2nd generation that doesn't burn out if you leave the ignition on while the motor is not running (like listening to the radio with motor off).
Jarred
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I believe Pilothyer is referring to the "fuel injection points" not the ignition points. They tell the fuel injectors when to squirt as opposed to firing the spark plugs.

Bob L: Thanks. I'm not familiar with D-jet. My system isn't of any help with that.

The question remains... Can this be adapted to replace the fuel injector "trigger points"?
Anyone?

Jarred.

Sent PM with questions.

The trigger points supply signal (continuity) to injector pairs 1-4 and 3-2, 180 degrees apart. The original trigger points often develop "bounce" which causes problems at idle and above. The center pin on the trigger point connector is common ground and the other two pins are positive for the injector pairs. If this device could supply continuity to the pairs 180 degrees apart it would replace the trigger points.

Neat setup, I like it...good price as well.







I'm sure Jarred could easily make a circuit and the trigger to do so...I made an electronic variation of the trigger in '05 ... it's ugly but it worked, never went past the prototype stage since I ended up going full aftermarket FI/ignition. The trigger is looking for a sinking (ground) signal from what I vaguely remember.

http://www.914world.com/bbs2/index.php?sho...c=24043&hl=

My system can't do it; it was designed to replace the points/rotor/cap for ignition triggering (and modern FI sync). Just browsing the d-jet into on the web it looks like the FI points/switches are down in the base of the distributor. It would be interesting to see if you could use two hall effect sensors to drive IGBT's that would then switch the injectors to ground instead of those mechanical points. Just depends on whether the cam on the distributor shaft would give a consistent trigger signal. It might need to be ground into a more square profile similar to a trigger wheel (wouldn't have to be exact). Lot of work just to modify a small part of a very antiquated injection system. Is there really a need out there for this?

Hi Jarred, see link right above your post...I made this circuit many moons ago and it did work, I think there is very small market...I had some interest from some Volvo guys that had D-jet as well, but never followed thru.

Feel free to pursue it further if you'd like, I no longer have a car or parts to test this out on and have plenty of other things to keep me busy right now.

Mueller: Thanks. It takes surprisingly long to develop and prototype a product that is manufacturable. I ran the batch of 10 mostly because when I have the cnc setup it's not a big deal to plug in more parts. We'll see if I ever make any more.

I just got one of these to try out and while I haven't used it yet, the quality is very good. It really is a nice production-quality part. Thanks Jarred!