Cameron Daline Posted August 9, 2010 Report Share Posted August 9, 2010 Hi all. I have an old Volvo 240 that I built a custom turbo motor for that I have running on LINK G3. It's all running beautifully and working great so far but I'm trying to tie up a couple more loose ends. I'm currently trying to figure out how to get the factory tacho to work with the LINK. The factory tacho originally ran off the negative side of the ignition coil. With the new motor I have it running on COP arrangement so no external coil to drive the factory tacho. Here's what I found, according to the LINK manual: Quote: "An auxiliary output configured at 'Tacho" produces a 0-12V pulse train to drive a low-level tach. There will be one output pulse for each time a cylinder reaches TDC. Connect an auxiliary output directly to a low-level tachometer. Link G3 ECU's will NOT drive a high level tach that is triggered by a coil's negative terminal. Using a high level tach on a multi-coil engine presents some problems, as each coils is not firing as often as a distributor engine's coil would. In this case the preferred solution is to modify the high level tach to accept a low level signal." I'd imagine I could wire the tach up by triggering off each coil and wiring in diodes to not send the signal back to the other coils, but single wire hookup off the ECU seems way easier since the ECU is already configured to send out the signal I need. I just don't get what is meant by the statement 'modify the high level tach to accept a low level signal.' I don't even know where to start with that? Can I just amplify the tach signal off the ECU somehow? Any thoughts? Quote Link to comment Share on other sites More sharing options...
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