BOSCH D-Jetronic Megasquirt Adapter Options

[shconer]

I have built a prototype board that adapts the factory Bosch D-Jetronic card edge connector in my 1969 Squareback to the DB-37 connector of my Megasquirt 2. Also I retrofitted the factory pressure sensor with a modern sensor inside. With some small modifications to the Megasquirt board to accommodate the external MAP sensor. I have created a plug and play system that works with the factory harness and does not require any further modifications or additions. Alternately you could instead connect the standard Megasquirt onboard MAP sensor with a hose to the manifold and lose the factory appearance. I have done some testing with the prototype board and I am in the final stages of developing the final version. I have designed it to be compatible with early and late type 3 cars as well as all fuel injected 914's. Before I ordered PCBs and components I thought I would see if there is any interest out there for something like this. The final PCB is designed to mount inside of the factory case with room for the Megasquirt. An assembled adapter would cost approximately $80 CAD. This could be a cheaper solution for someone with a malfunctioning D-Jet ECU or a dual carb conversion. The factory idle control system still controls idle. This is a fuel only set up and the factory distributor and ignition is used. Also there is no provision for EGO feedback, it is a open loop system. This adapter works with MS1 or MS2 V3.0/3.52.

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864953.1.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864953.2.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864954.3.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864954.4.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864955.5.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/clubveedub.ca-17863-1409864955.6.jpg)

[shconer]

I am still working on the design. I have since discovered how the factory late Type 3 and Type 4 TVS works. I have been working on making the board compatible with the factory TVS sensor. I might make a few non TVS compatible boards to test the basic design and my application does not require it.

The adapter does use the factory fuel injection points. If a custom harness was made a hall sensor could be used. But it might be difficult to find a connector that works. Also with no ignition control and all 4 injectors firing at the same time, the more accurate crankshaft position information might not be worth it. The factory D-Jet batch fires based on which contact is triggered. But I think simultaneous injection is the only way it can be done with the Megasquirt and the factory fuel injection points. Also having only one injector driver keeps the cost down and the engine might run a little cooler. As far as having issues with the low pulse width, only testing will tell but this has not been my experience in my application but it could be a possibility.