I thought up a little project a while back... microcontroller controlled spark advance and dwell. What I need to do is use the tach signal from the HEI module to do all the calculations. What I'm finding is the module itself does not seem to put out a tach signal (at least that I can measure with my meter). I am assuming I need to use a pull up resistor on the tach line, but wanted to see if anyone knew for sure before I try anything more (I kind of cooked the project trying things already).
I had the whole setup put together and working by feeding a 5v pulse to the + side of the vr sensor on my table. It even put out it's own tach signal then, but once installed and connected to the distributor I lost the tach signal, but the engine does run.
Just to shed some light on the mechanicals it's a Durspark to HEI swap by means of chucking the Duraspark box and wiring a HEI module in it's place. I'm kind of hoping to improve on the idea a little...
I had the whole setup put together and working by feeding a 5v pulse to the + side of the vr sensor on my table. It even put out it's own tach signal then, but once installed and connected to the distributor I lost the tach signal, but the engine does run.
Just to shed some light on the mechanicals it's a Durspark to HEI swap by means of chucking the Duraspark box and wiring a HEI module in it's place. I'm kind of hoping to improve on the idea a little...
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