Once the engine block was reinstalled the next job was the Miller chip conversion. I had received the kit plus the air intake some time earlier but was too busy with the engine overhaul to look at it. My ECU is the 059 model so the first job was to open it up and modify the board to accept the 28 pin chip. Miller had supplied me with a couple of socket extensions to add to the existing 24 pin socket but I didn’t like the idea and decided to remove the existing socket and replace it with a new 28 pin. This can be a sensitive job as far as the temperature of the iron is concerned but I have a quality digital solder station and it all went smoothly. To remove the old socket I just used de-soldering braid to absorb the molten solder until all the pins were clean and free of the board. Next the new socket was soldered in place ready to accept the new chip. With the new chip in place the ECU casing can be re-assembled.
The Miller installation manual is good and if you follow it the installation is not difficult but I’m not always satisfied with a particular installation method and tend to make my own customisation. This was also the case with the re-wiring necessary to get the chip to work with the Bosch MAF sensor. I didn’t like the idea of completely rewiring the ECU plug and sealing it all up again as I might find myself in the situation that something breaks and I have to revert to the old AFM and BMW chip. With this in mind I re-routed the wiring through a switch so it could easily be switched back to standard without having to do any resoldering.
The next thing I was not completely happy with was the Bosch MAF sensor. It is a standard modern Bosch unit which is used in various car models but it looks a bit plain and doesn’t exactly fit with the 80’s character of the engine bay. So I set about first making some drawings of an aluminium casing in Autocad and then created the two halves needed using my lathe and milling machine. The machine reliefs were painted black to match the powder coated valve cover and a plastified Miller logo was glued in a circular relief on the the top.
Lastly the air filter kit as supplied didn’t actually fit too well as I wanted it in the bay. It was also delivered with a blue silicon connecting tube which I also felt didn’t look right in the engine bay. So I ended up chopping the stainless tube down and making some modifications to get it to sit just like the original air filter box. It also makes use of the original black rubber elbow which connects the AFM with the filter box.
This is all shown in the following slide show.
