Got home from work, found a nice little box in the mailbox (pre-built V4) and now I am up and running just a few hours later. I did all the time consuming stuff over the past couple weekends - getting the crank pulley off was about the hardest part, but gave me an excuse to buy a new compressor and an impact wrench.
I had the car up and running on the EDIS limp home mode last weekend and had all the wires ran and ready to go into the molex (except the tach hookup, I will tackle that soon).
I played around with different maps and learned to use the software. Should be out driving tomorrow and tweaking my map. I will post some pics in the gallery eventually. Car is a 1975 BMW 2002.
Thanks Brent!
T.J.
Thanks Brent!
Moderators: JeffC, rdoherty, stieg, brentp
Tach work around
I finished the last part of this project today. My factory tach used to be connected the the (-) coil terminal, so I didn't even try to hook it up to one of the nice square wave sources that newer tachs seem to like. I went straight for the two diodes to combine the two coil signals and the zener diode like so many have seemed to use. It didn't work at all for me. After I added a 100k resistor in parallel with one of the diodes the tach worked great as long as engine RPM was below 2,000 rpm. Above 2,000 rpm the tach would indicate zero.
I tried adding a resistor to ground where I found someone on the internet said they had success with and that didn't work any differently. I figured the zener diode is in the circuit to drop it's rated voltage. Studying up on various web sites the best I could figure the new signal and the old signal are similar in nature (the EDIS version being cleaner and with a higher amplitude pulse). I assumed that it was the amplitude of the signal at higher rpms that was overdriving the tach circuit and causing it to indicate zero. After driving around all last week with the tach disconnected, today I decided to try another approach. If the problem was a too large of a pulse I would make it smaller. Not by the zener breakdown voltage, but down by half and see what happened.
I made a voltage divider by using two 100k resistors after the two combining diodes. Grounded the the downstream side of the second resistor and connected the tach input wire between the two resistors. The temporary setup worked like a champ, so I removed it and put it back together more permanently and went for a test drive. Works well. I may go back and try two larger resistors to limit the amount of current going to ground through my voltage divider. I am assuming my tach has a relatively high input impedance - didn't measure it, but since it seems to work just fine as is, maybe I'll leave it alone. I still owe some pics of the car and the installation for the gallery - I will get some in there soon.
I tried adding a resistor to ground where I found someone on the internet said they had success with and that didn't work any differently. I figured the zener diode is in the circuit to drop it's rated voltage. Studying up on various web sites the best I could figure the new signal and the old signal are similar in nature (the EDIS version being cleaner and with a higher amplitude pulse). I assumed that it was the amplitude of the signal at higher rpms that was overdriving the tach circuit and causing it to indicate zero. After driving around all last week with the tach disconnected, today I decided to try another approach. If the problem was a too large of a pulse I would make it smaller. Not by the zener breakdown voltage, but down by half and see what happened.
I made a voltage divider by using two 100k resistors after the two combining diodes. Grounded the the downstream side of the second resistor and connected the tach input wire between the two resistors. The temporary setup worked like a champ, so I removed it and put it back together more permanently and went for a test drive. Works well. I may go back and try two larger resistors to limit the amount of current going to ground through my voltage divider. I am assuming my tach has a relatively high input impedance - didn't measure it, but since it seems to work just fine as is, maybe I'll leave it alone. I still owe some pics of the car and the installation for the gallery - I will get some in there soon.